<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019cba81-daff-7044-8c14-a92fbb257d59,g:b6d4e628-e8f7-4e5f-9953-e1b19041ffa1-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.fnb-online.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="fnb-20260331.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019cba81-e0a0-7562-8d1e-945ce5994ee3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndDueFromBanks_019cba81-e0a0-7dfa-8143-6424c6aebdec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndDueFromBanks"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019cba81-e0a0-7562-8d1e-945ce5994ee3" xlink:to="loc_us-gaap_CashAndDueFromBanks_019cba81-e0a0-7dfa-8143-6424c6aebdec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositsInBanks_019cba81-e0a0-7453-a1e2-b3a5ed899d64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestBearingDepositsInBanks"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019cba81-e0a0-7562-8d1e-945ce5994ee3" xlink:to="loc_us-gaap_InterestBearingDepositsInBanks_019cba81-e0a0-7453-a1e2-b3a5ed899d64" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019cba81-e0a0-73fa-a80b-f748ef6dd233" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019cba81-e0a0-73fa-a80b-f748ef6dd233" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e0a0-7a1d-9e7f-0a69dca1f578" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e0a0-7a1d-9e7f-0a69dca1f578" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e0a0-7b99-87d6-be605551712d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e0a0-7b99-87d6-be605551712d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_FinancingReceivableHeldForSaleNetNotPartOfDisposalGroupExcludingAccruedInterest_019cba81-e0a0-7d2c-8b34-50a5e6251298" xlink:href="fnb-20260331.xsd#fnb_FinancingReceivableHeldForSaleNetNotPartOfDisposalGroupExcludingAccruedInterest"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_fnb_FinancingReceivableHeldForSaleNetNotPartOfDisposalGroupExcludingAccruedInterest_019cba81-e0a0-7d2c-8b34-50a5e6251298" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019cba81-e0a0-7fc9-a58e-3eea6059a718" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019cba81-e0a0-7fc9-a58e-3eea6059a718" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019cba81-e0a0-7616-9621-d6c9fee6ee2e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_Goodwill_019cba81-e0a0-7616-9621-d6c9fee6ee2e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019cba81-e0a0-7981-b338-bedf3ec83b42" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019cba81-e0a0-7981-b338-bedf3ec83b42" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsurance_019cba81-e0a0-70bd-9a91-9e03f2d77711" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BankOwnedLifeInsurance"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_BankOwnedLifeInsurance_019cba81-e0a0-70bd-9a91-9e03f2d77711" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets_019cba81-e0a0-70e8-a433-e1a2827d0354" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssets"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_OtherAssets_019cba81-e0a0-70e8-a433-e1a2827d0354" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019cba81-e0a0-7b05-a58d-ae1ce117bacf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019cba81-e0a0-7d67-b7b2-f3f02ba4054c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization_019cba81-e0a0-7b05-a58d-ae1ce117bacf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019cba81-e0a0-76ab-8717-60c75ca171b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019cba81-e0a0-77a1-b324-100db4999ec5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019cba81-e0a0-76ab-8717-60c75ca171b7" xlink:to="loc_us-gaap_Liabilities_019cba81-e0a0-77a1-b324-100db4999ec5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7789-bba4-3372a58c74c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019cba81-e0a0-76ab-8717-60c75ca171b7" xlink:to="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7789-bba4-3372a58c74c1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7dd1-ac9e-4058656dad87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019cba81-e0a0-7e82-8955-072c34e9ed69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7dd1-ac9e-4058656dad87" xlink:to="loc_us-gaap_CommonStockValue_019cba81-e0a0-7e82-8955-072c34e9ed69" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019cba81-e0a0-7fdd-a87c-30f02edfda41" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7dd1-ac9e-4058656dad87" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019cba81-e0a0-7fdd-a87c-30f02edfda41" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019cba81-e0a0-77e2-a350-bea9ead1c69a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7dd1-ac9e-4058656dad87" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019cba81-e0a0-77e2-a350-bea9ead1c69a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019cba81-e0a0-7b39-9d02-9fc43235f956" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7dd1-ac9e-4058656dad87" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019cba81-e0a0-7b39-9d02-9fc43235f956" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_019cba81-e0a0-7996-933f-39affe12ece4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019cba81-e0a0-7dd1-ac9e-4058656dad87" xlink:to="loc_us-gaap_TreasuryStockCommonValue_019cba81-e0a0-7996-933f-39affe12ece4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019cba81-e0a0-7696-9a28-6fb7ecab4005" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_019cba81-e0a0-7fbb-9cca-2c9ba858fa1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Deposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019cba81-e0a0-7696-9a28-6fb7ecab4005" xlink:to="loc_us-gaap_Deposits_019cba81-e0a0-7fbb-9cca-2c9ba858fa1e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_019cba81-e0a0-744e-8002-7f41943f16b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermBorrowings"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019cba81-e0a0-7696-9a28-6fb7ecab4005" xlink:to="loc_us-gaap_ShortTermBorrowings_019cba81-e0a0-744e-8002-7f41943f16b1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019cba81-e0a0-7ebc-8712-2bd5fde71a76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019cba81-e0a0-7696-9a28-6fb7ecab4005" xlink:to="loc_us-gaap_LongTermDebt_019cba81-e0a0-7ebc-8712-2bd5fde71a76" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_019cba81-e0a0-7892-a030-2d7211d3d544" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019cba81-e0a0-7696-9a28-6fb7ecab4005" xlink:to="loc_us-gaap_OtherLiabilities_019cba81-e0a0-7892-a030-2d7211d3d544" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_019cba81-e0a0-7ae0-a67e-438d78454893" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Deposits"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDepositLiabilities_019cba81-e0a0-7f75-bc2a-8fc504b11848" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestBearingDepositLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019cba81-e0a0-7ae0-a67e-438d78454893" xlink:to="loc_us-gaap_NoninterestBearingDepositLiabilities_019cba81-e0a0-7f75-bc2a-8fc504b11848" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositLiabilities_019cba81-e0a0-711f-b0a6-3517b3cb071e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestBearingDepositLiabilities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019cba81-e0a0-7ae0-a67e-438d78454893" xlink:to="loc_us-gaap_InterestBearingDepositLiabilities_019cba81-e0a0-711f-b0a6-3517b3cb071e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019cba81-e0a0-77a4-9fdb-66167c01495c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e0a0-7718-af55-ea321f03991b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019cba81-e0a0-77a4-9fdb-66167c01495c" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e0a0-7718-af55-ea321f03991b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019cba81-e0a0-747d-ae77-075fe922ac0f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019cba81-e0a0-77a4-9fdb-66167c01495c" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019cba81-e0a0-747d-ae77-075fe922ac0f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="fnb-20260331.xsd#CONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_ServiceCharges_019cba81-e0a0-7589-80f0-30507bbaefdd" xlink:href="fnb-20260331.xsd#fnb_ServiceCharges"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_fnb_ServiceCharges_019cba81-e0a0-7589-80f0-30507bbaefdd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_TrustServices_019cba81-e0a0-794c-bcd0-9230f43f7e20" xlink:href="fnb-20260331.xsd#fnb_TrustServices"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_fnb_TrustServices_019cba81-e0a0-794c-bcd0-9230f43f7e20" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InsuranceCommissionsAndFees_019cba81-e0a0-759b-96e0-e24a2ad3039e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InsuranceCommissionsAndFees"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_us-gaap_InsuranceCommissionsAndFees_019cba81-e0a0-759b-96e0-e24a2ad3039e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions_019cba81-e0a0-75cb-8d80-7283f75448b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_us-gaap_InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions_019cba81-e0a0-75cb-8d80-7283f75448b8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_CapitalMarketsIncome_019cba81-e0a0-75b1-b988-0d8fe0675e5c" xlink:href="fnb-20260331.xsd#fnb_CapitalMarketsIncome"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_fnb_CapitalMarketsIncome_019cba81-e0a0-75b1-b988-0d8fe0675e5c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_MortgageBankingOperatingIncome_019cba81-e0a0-79a0-afc5-c5e44eeb7cd7" xlink:href="fnb-20260331.xsd#fnb_MortgageBankingOperatingIncome"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_fnb_MortgageBankingOperatingIncome_019cba81-e0a0-79a0-afc5-c5e44eeb7cd7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_DividendsonNonmarketableEquitySecurities_019cba81-e0a0-75d4-a8d8-8211f3058c32" xlink:href="fnb-20260331.xsd#fnb_DividendsonNonmarketableEquitySecurities"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_fnb_DividendsonNonmarketableEquitySecurities_019cba81-e0a0-75d4-a8d8-8211f3058c32" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsuranceIncome_019cba81-e0a0-728d-a1ab-1d2bfbd5c176" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BankOwnedLifeInsuranceIncome"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_us-gaap_BankOwnedLifeInsuranceIncome_019cba81-e0a0-728d-a1ab-1d2bfbd5c176" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeOther_019cba81-e0a0-723d-84f6-213d1cc55383" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestIncomeOther"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_us-gaap_NoninterestIncomeOther_019cba81-e0a0-723d-84f6-213d1cc55383" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_InterchangeAndCardTransactionFees_019cba81-e0a0-73d0-acd9-68b95f937463" xlink:href="fnb-20260331.xsd#fnb_InterchangeAndCardTransactionFees"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7840-aa73-1141f678f73c" xlink:to="loc_fnb_InterchangeAndCardTransactionFees_019cba81-e0a0-73d0-acd9-68b95f937463" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketingExpense_019cba81-e0a0-7dd4-aa68-3a9d666886bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MarketingExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_MarketingExpense_019cba81-e0a0-7dd4-aa68-3a9d666886bd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_019cba81-e0a0-7910-8004-396983068dd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_OtherNoninterestExpense_019cba81-e0a0-7910-8004-396983068dd9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentExpense_019cba81-e0a0-75d3-a306-4b6e87a4cf76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquipmentExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_EquipmentExpense_019cba81-e0a0-75d3-a306-4b6e87a4cf76" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_019cba81-e0a0-7e39-a2a6-d5f1c50fb12e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalDepositInsuranceCorporationPremiumExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_019cba81-e0a0-7e39-a2a6-d5f1c50fb12e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxesExcludingIncomeAndExciseTaxes_019cba81-e0a0-7a93-89a5-d1904c8bdb87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxesExcludingIncomeAndExciseTaxes"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_TaxesExcludingIncomeAndExciseTaxes_019cba81-e0a0-7a93-89a5-d1904c8bdb87" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_019cba81-e0a0-765a-bfaa-8bfe4e02891b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OccupancyNet"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_OccupancyNet_019cba81-e0a0-765a-bfaa-8bfe4e02891b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019cba81-e0a0-7161-90e0-2ee497e81206" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019cba81-e0a0-7161-90e0-2ee497e81206" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_019cba81-e0a0-77c7-b7db-f464a663ac30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfessionalFees"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7521-bd82-5b2ac44bf283" xlink:to="loc_us-gaap_ProfessionalFees_019cba81-e0a0-77c7-b7db-f464a663ac30" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_019cba81-e0a0-7dff-a343-3fc9f6d8aa1e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseOperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDeposits_019cba81-e0a0-7475-887d-691deaf821cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseDeposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseOperating_019cba81-e0a0-7dff-a343-3fc9f6d8aa1e" xlink:to="loc_us-gaap_InterestExpenseDeposits_019cba81-e0a0-7475-887d-691deaf821cc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseShortTermBorrowings_019cba81-e0a0-7f30-af8b-b9c731fbd0e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseShortTermBorrowings"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseOperating_019cba81-e0a0-7dff-a343-3fc9f6d8aa1e" xlink:to="loc_us-gaap_InterestExpenseShortTermBorrowings_019cba81-e0a0-7f30-af8b-b9c731fbd0e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseLongTermDebt_019cba81-e0a0-787c-bf1c-9bbe1f856d95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseLongTermDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseOperating_019cba81-e0a0-7dff-a343-3fc9f6d8aa1e" xlink:to="loc_us-gaap_InterestExpenseLongTermDebt_019cba81-e0a0-787c-bf1c-9bbe1f856d95" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019cba81-e0a0-7a23-8a7c-19783c5c021b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cba81-e0a0-7776-b53c-c47601043bcb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019cba81-e0a0-7a23-8a7c-19783c5c021b" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cba81-e0a0-7776-b53c-c47601043bcb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019cba81-e0a0-71f1-ad0d-f6b2b6d029e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019cba81-e0a0-7a23-8a7c-19783c5c021b" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019cba81-e0a0-71f1-ad0d-f6b2b6d029e1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cba81-e0a0-7482-a71b-391b82f74f28" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_019cba81-e0a0-7d34-b6b6-874b116d3b2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cba81-e0a0-7482-a71b-391b82f74f28" xlink:to="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_019cba81-e0a0-7d34-b6b6-874b116d3b2c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7cc4-8f8a-361875bf586c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestIncome"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cba81-e0a0-7482-a71b-391b82f74f28" xlink:to="loc_us-gaap_NoninterestIncome_019cba81-e0a0-7cc4-8f8a-361875bf586c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7bb0-9980-7f1b0a8cf9ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestExpense"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019cba81-e0a0-7482-a71b-391b82f74f28" xlink:to="loc_us-gaap_NoninterestExpense_019cba81-e0a0-7bb0-9980-7f1b0a8cf9ed" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_019cba81-e0a0-742f-8921-6ecabd780572" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_019cba81-e0a0-70e3-ad03-5a5f437b5b84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_019cba81-e0a0-742f-8921-6ecabd780572" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_019cba81-e0a0-70e3-ad03-5a5f437b5b84" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_019cba81-e0a0-7fb9-8c80-120dfa3d9b64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseOperating"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_019cba81-e0a0-742f-8921-6ecabd780572" xlink:to="loc_us-gaap_InterestExpenseOperating_019cba81-e0a0-7fb9-8c80-120dfa3d9b64" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_019cba81-e0a0-7085-a13f-9442084a0c73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxable_019cba81-e0a0-7907-98f1-6b85ed70b7e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeSecuritiesTaxable"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019cba81-e0a0-7085-a13f-9442084a0c73" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxable_019cba81-e0a0-7907-98f1-6b85ed70b7e6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_019cba81-e0a0-7b62-aa38-e87e31121676" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019cba81-e0a0-7085-a13f-9442084a0c73" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_019cba81-e0a0-7b62-aa38-e87e31121676" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInterestAndDividendIncome_019cba81-e0a0-7120-ba3c-fa40d32be6cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherInterestAndDividendIncome"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019cba81-e0a0-7085-a13f-9442084a0c73" xlink:to="loc_us-gaap_OtherInterestAndDividendIncome_019cba81-e0a0-7120-ba3c-fa40d32be6cb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio_019cba81-e0a0-7a2f-a402-aadada643251" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019cba81-e0a0-7085-a13f-9442084a0c73" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio_019cba81-e0a0-7a2f-a402-aadada643251" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_019cba81-e0a0-7701-8d99-7552868571e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_019cba81-e0a0-7edc-b7ee-70e4d34e5a4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_019cba81-e0a0-7701-8d99-7552868571e7" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_019cba81-e0a0-7edc-b7ee-70e4d34e5a4a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_019cba81-e0a0-7fe1-8891-3e6c9da473ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_019cba81-e0a0-7701-8d99-7552868571e7" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_019cba81-e0a0-7fe1-8891-3e6c9da473ec" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="simple" xlink:href="fnb-20260331.xsd#CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e0a0-7761-91de-dea3fad83a46" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_019cba81-e0a0-72bc-a243-7f20f5020418" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e0a0-7761-91de-dea3fad83a46" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_019cba81-e0a0-72bc-a243-7f20f5020418" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_019cba81-e0a0-78a6-bc6e-d089188914fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e0a0-7761-91de-dea3fad83a46" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax_019cba81-e0a0-78a6-bc6e-d089188914fd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax_019cba81-e0a0-78cb-bb6e-2f9efcb04c62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e0a0-7761-91de-dea3fad83a46" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax_019cba81-e0a0-78cb-bb6e-2f9efcb04c62" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_019cba81-e0a0-7ec8-9429-18e4e988cf7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e0a0-7761-91de-dea3fad83a46" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_019cba81-e0a0-7ec8-9429-18e4e988cf7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019cba81-e0a0-7c8b-9e26-35d8a531d40c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019cba81-e0a0-75f4-a906-0d331300325a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019cba81-e0a0-7c8b-9e26-35d8a531d40c" xlink:to="loc_us-gaap_NetIncomeLoss_019cba81-e0a0-75f4-a906-0d331300325a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e0a0-7a6c-bf64-d46016b158d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019cba81-e0a0-7c8b-9e26-35d8a531d40c" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e0a0-7a6c-bf64-d46016b158d5" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="fnb-20260331.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromRepaymentsOfShortTermDebt_019cba81-e142-7cb4-8ffd-ee62a2a732c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromRepaymentsOfShortTermDebt"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:to="loc_us-gaap_ProceedsFromRepaymentsOfShortTermDebt_019cba81-e142-7cb4-8ffd-ee62a2a732c8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019cba81-e142-7b45-8849-838da0f6adf0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019cba81-e142-7b45-8849-838da0f6adf0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_019cba81-e142-74dd-9cfa-0d2d4fb679f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_019cba81-e142-74dd-9cfa-0d2d4fb679f1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019cba81-e142-79c7-a8f2-14937bfe2f45" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019cba81-e142-79c7-a8f2-14937bfe2f45" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_019cba81-e142-7904-8ab4-bee9b65f8e18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsOfDividendsCommonStock"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_019cba81-e142-7904-8ab4-bee9b65f8e18" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_019cba81-e142-7a2a-92a6-1000cf54dc47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_019cba81-e142-7a2a-92a6-1000cf54dc47" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInDemandDeposits_019d67a4-09e4-7c47-987b-2c77b2235bdc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInDemandDeposits"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7577-89e3-695a83bfdc45" xlink:to="loc_us-gaap_IncreaseDecreaseInDemandDeposits_019d67a4-09e4-7c47-987b-2c77b2235bdc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019cba81-e142-74a3-bbb9-58e7424aecd7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7dbe-a293-a2b43d896f81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019cba81-e142-74a3-bbb9-58e7424aecd7" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7dbe-a293-a2b43d896f81" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-73d6-a1d9-7cc28c26f96f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019cba81-e142-74a3-bbb9-58e7424aecd7" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-73d6-a1d9-7cc28c26f96f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7cdb-a8b7-34d9b399cdf2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019cba81-e142-74a3-bbb9-58e7424aecd7" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019cba81-e142-7cdb-a8b7-34d9b399cdf2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019cba81-e142-796e-80b8-3a1faae60915" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_NetIncomeLoss_019cba81-e142-796e-80b8-3a1faae60915" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAmortizationAndAccretionNet_019cba81-e142-76fd-b9ea-058f6d1b3e58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationAmortizationAndAccretionNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_DepreciationAmortizationAndAccretionNet_019cba81-e142-76fd-b9ea-058f6d1b3e58" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_019cba81-e142-74fe-b4b8-5010e654a28f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal_019cba81-e142-74fe-b4b8-5010e654a28f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_019cba81-e142-7f62-b6bb-907942283c55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxesAndTaxCredits"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_019cba81-e142-7f62-b6bb-907942283c55" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToPurchaseLoansHeldForSale_019cba81-e142-7968-9758-a47019a83259" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToPurchaseLoansHeldForSale"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_PaymentsToPurchaseLoansHeldForSale_019cba81-e142-7968-9758-a47019a83259" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfLoansHeldForSale_019cba81-e142-7705-9706-bd95686e997a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfLoansHeldForSale"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_ProceedsFromSaleOfLoansHeldForSale_019cba81-e142-7705-9706-bd95686e997a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_GainLossOnSaleOfFinancingReceivables_019cba81-e142-7431-8b79-fcc6e2c43b94" xlink:href="fnb-20260331.xsd#fnb_GainLossOnSaleOfFinancingReceivables"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_fnb_GainLossOnSaleOfFinancingReceivables_019cba81-e142-7431-8b79-fcc6e2c43b94" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_019cba81-e142-751f-893b-bfb58ef9ec9b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_019cba81-e142-751f-893b-bfb58ef9ec9b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_019cba81-e142-7fc5-88f6-280351b4a5ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInInterestPayableNet"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_019cba81-e142-7fc5-88f6-280351b4a5ec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_019cba81-e142-7335-887b-db8d922e6b60" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_019cba81-e142-7335-887b-db8d922e6b60" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019cba81-e142-745d-b852-2f1a0b07d6b3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019cba81-e142-7e5b-8afc-9d0f19ddc23a" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019cba81-e142-745d-b852-2f1a0b07d6b3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_PaymentsForProceedsFromFinancingReceivables_019cba81-e142-711b-826d-dd7c83d7a7f9" xlink:href="fnb-20260331.xsd#fnb_PaymentsForProceedsFromFinancingReceivables"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:to="loc_fnb_PaymentsForProceedsFromFinancingReceivables_019cba81-e142-711b-826d-dd7c83d7a7f9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019cba81-e142-74d2-b0cf-b7549f5e5d64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019cba81-e142-74d2-b0cf-b7549f5e5d64" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_019cba81-e142-7bf1-b472-c3dde848a7d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_019cba81-e142-7bf1-b472-c3dde848a7d5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireHeldToMaturitySecurities_019cba81-e142-7a68-959b-471a007cd784" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireHeldToMaturitySecurities"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:to="loc_us-gaap_PaymentsToAcquireHeldToMaturitySecurities_019cba81-e142-7a68-959b-471a007cd784" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities_019cba81-e142-730c-85c2-f368cebcce7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities_019cba81-e142-730c-85c2-f368cebcce7b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019cba81-e142-76ef-8c22-2843ee13baa4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019cba81-e142-76ef-8c22-2843ee13baa4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfLoansAndLeasesHeldForInvestment_019df89f-0c91-7611-bc5f-139ea0e6b8f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfLoansAndLeasesHeldForInvestment"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019cba81-e142-75b5-8b79-e443246e68c9" xlink:to="loc_us-gaap_ProceedsFromSaleOfLoansAndLeasesHeldForInvestment_019df89f-0c91-7611-bc5f-139ea0e6b8f6" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesAvailableforSaleDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesAvailableforSaleDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesAvailableforSaleDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7acf-b15f-eee72667bf4d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e142-7503-83fe-6832b728b1f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7acf-b15f-eee72667bf4d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e142-7503-83fe-6832b728b1f1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019cba81-e142-7503-9195-45d9a060e764" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7acf-b15f-eee72667bf4d" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019cba81-e142-7503-9195-45d9a060e764" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019cba81-e142-748c-8c02-9565f31bd34e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7acf-b15f-eee72667bf4d" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019cba81-e142-748c-8c02-9565f31bd34e" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesHeldtoMaturityDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesHeldtoMaturityDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesHeldtoMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7b7a-bccb-02c4b8d5541d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_019cba81-e142-7c36-999a-63117511433b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7b7a-bccb-02c4b8d5541d" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_019cba81-e142-7c36-999a-63117511433b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019cba81-e142-7b94-b3d2-f5ec9e051069" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7b7a-bccb-02c4b8d5541d" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019cba81-e142-7b94-b3d2-f5ec9e051069" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_019cba81-e142-7c36-afaa-1acdd91852f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7b7a-bccb-02c4b8d5541d" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_019cba81-e142-7c36-afaa-1acdd91852f3" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesbyContractualMaturitiesDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesbyContractualMaturitiesDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofAmortizedCostandFairValueofSecuritiesbyContractualMaturitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019cba81-e142-7aeb-afce-b57f1d8ff054" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_019cba81-e142-7a61-8470-7deba244708a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019cba81-e142-7aeb-afce-b57f1d8ff054" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_019cba81-e142-7a61-8470-7deba244708a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_019cba81-e142-7237-86d7-20f0d85b8e3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019cba81-e142-7aeb-afce-b57f1d8ff054" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_019cba81-e142-7237-86d7-20f0d85b8e3b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7fa1-91d2-1449b295d325" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_019cba81-e142-7209-830f-478e70dc6bf6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7fa1-91d2-1449b295d325" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_019cba81-e142-7209-830f-478e70dc6bf6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_019cba81-e142-74ef-93f5-3b9a78dbe2e5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7fa1-91d2-1449b295d325" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_019cba81-e142-74ef-93f5-3b9a78dbe2e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_019cba81-e142-7884-8da3-3f2c43b1f5c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7fa1-91d2-1449b295d325" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost_019cba81-e142-7884-8da3-3f2c43b1f5c2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_019cba81-e142-72bd-9e45-891b6d4fe540" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7fa1-91d2-1449b295d325" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost_019cba81-e142-72bd-9e45-891b6d4fe540" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019cba81-e142-7a4d-8f69-5218e3424c72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019cba81-e142-7b8d-a907-3ca67b186e3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019cba81-e142-7a4d-8f69-5218e3424c72" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019cba81-e142-7b8d-a907-3ca67b186e3b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019cba81-e142-73ed-a1a0-6dd00ddb89c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019cba81-e142-7a4d-8f69-5218e3424c72" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019cba81-e142-73ed-a1a0-6dd00ddb89c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_019cba81-e142-7878-90a8-bfea8d06165d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019cba81-e142-7a4d-8f69-5218e3424c72" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_019cba81-e142-7878-90a8-bfea8d06165d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_019cba81-e142-7001-bae5-3832ed756085" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019cba81-e142-7a4d-8f69-5218e3424c72" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue_019cba81-e142-7001-bae5-3832ed756085" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7352-a487-a591a4f4af0f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount_019cba81-e142-7765-a633-0f0ddbe1b853" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7352-a487-a591a4f4af0f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount_019cba81-e142-7765-a633-0f0ddbe1b853" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount_019cba81-e142-77ac-a897-ea1359e5227e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7352-a487-a591a4f4af0f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount_019cba81-e142-77ac-a897-ea1359e5227e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount_019cba81-e142-79f2-a40b-3d915a3dc430" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7352-a487-a591a4f4af0f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount_019cba81-e142-79f2-a40b-3d915a3dc430" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount_019cba81-e142-7f08-b275-bf46564bd609" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7352-a487-a591a4f4af0f" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount_019cba81-e142-7f08-b275-bf46564bd609" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7bde-924e-59f9e3d925fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_019cba81-e142-70f7-b35b-9469dd742831" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7bde-924e-59f9e3d925fa" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_019cba81-e142-70f7-b35b-9469dd742831" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7388-8e0c-582858324149" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7bde-924e-59f9e3d925fa" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7388-8e0c-582858324149" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e142-7785-853a-1223bbcf3640" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_019cba81-e142-757a-a12c-dead7712b60e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e142-7785-853a-1223bbcf3640" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_019cba81-e142-757a-a12c-dead7712b60e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019cba81-e142-7a37-8ad8-90501e4dc0a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e142-7785-853a-1223bbcf3640" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019cba81-e142-7a37-8ad8-90501e4dc0a0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7c8b-92da-e2c22258a953" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount_019cba81-e142-7175-a477-8aa17d93d3be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7c8b-92da-e2c22258a953" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateNetCarryingAmount_019cba81-e142-7175-a477-8aa17d93d3be" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7865-87e8-5297bf952077" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7c8b-92da-e2c22258a953" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019cba81-e142-7865-87e8-5297bf952077" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_019cba81-e142-7065-b48e-e07f54cecd0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue_019cba81-e142-7fe1-a875-5b06715727d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_019cba81-e142-7065-b48e-e07f54cecd0e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue_019cba81-e142-7fe1-a875-5b06715727d2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019cba81-e142-791c-844f-6b35f903b235" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_019cba81-e142-7065-b48e-e07f54cecd0e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019cba81-e142-791c-844f-6b35f903b235" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_019cba81-e142-7b73-9d0e-a09896bce7d0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_019cba81-e142-7065-b48e-e07f54cecd0e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue_019cba81-e142-7b73-9d0e-a09896bce7d0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue_019cba81-e142-7559-b688-93ebd97e74f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue_019cba81-e142-7065-b48e-e07f54cecd0e" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue_019cba81-e142-7559-b688-93ebd97e74f6" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofFairValuesandUnrealizedLossesofImpairedSecuritiesbyLengthofImpairmentDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#INVESTMENTSECURITIESScheduleofFairValuesandUnrealizedLossesofImpairedSecuritiesbyLengthofImpairmentDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/INVESTMENTSECURITIESScheduleofFairValuesandUnrealizedLossesofImpairedSecuritiesbyLengthofImpairmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_019cba81-e142-7f11-b9f1-b8b848553a3d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_019cba81-e142-7fd3-8a62-4076798f2502" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_019cba81-e142-7f11-b9f1-b8b848553a3d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions_019cba81-e142-7fd3-8a62-4076798f2502" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_019cba81-e142-7513-a4c6-fd45e5bae35c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions_019cba81-e142-7f11-b9f1-b8b848553a3d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions_019cba81-e142-7513-a4c6-fd45e5bae35c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019cba81-e142-7fac-b89e-03d6d2d81ac9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019cba81-e142-7c98-9750-a96860e20353" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019cba81-e142-7fac-b89e-03d6d2d81ac9" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019cba81-e142-7c98-9750-a96860e20353" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019cba81-e142-7eab-b6b9-117669b53fae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019cba81-e142-7fac-b89e-03d6d2d81ac9" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019cba81-e142-7eab-b6b9-117669b53fae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019cba81-e142-7bb5-9643-4bad537ec7bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019cba81-e142-7136-8d3e-f5c75e4c06cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019cba81-e142-7bb5-9643-4bad537ec7bf" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019cba81-e142-7136-8d3e-f5c75e4c06cf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019cba81-e142-7cc1-952f-582b81ce0efd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019cba81-e142-7bb5-9643-4bad537ec7bf" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019cba81-e142-7cc1-952f-582b81ce0efd" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/LOANSANDLEASESScheduleofOriginationYearDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#LOANSANDLEASESScheduleofOriginationYearDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/LOANSANDLEASESScheduleofOriginationYearDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_019cba81-e142-79b0-8002-4bf4f17da3db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff_019cba81-e142-79b0-8002-4bf4f17da3db" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-7d07-9a39-e665915306c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-7d07-9a39-e665915306c9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019cba81-e142-78f0-97d7-be70735bdb32" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019cba81-e142-78f0-97d7-be70735bdb32" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-7c6e-9821-4623e0d3ef2d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-7c6e-9821-4623e0d3ef2d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff_019cba81-e142-7266-b96b-3ff7d42523e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingWriteoff_019cba81-e142-7266-b96b-3ff7d42523e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-73b6-a814-49b5c2be8a2e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-73b6-a814-49b5c2be8a2e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-7c4c-bc96-262a48f5c7ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e142-7616-91cc-fd9768981628" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019cba81-e142-7c4c-bc96-262a48f5c7ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_019cba81-e142-74fd-a87b-7ec58ba3148c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_019cba81-e142-74fd-a87b-7ec58ba3148c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolving_019cba81-e142-76cc-9158-12008ab5a3a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolving"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolving_019cba81-e142-76cc-9158-12008ab5a3a0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_019cba81-e142-7b55-968b-dff0264f0e98" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_019cba81-e142-7b55-968b-dff0264f0e98" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_019cba81-e142-76f9-951b-554317a2d3a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_019cba81-e142-76f9-951b-554317a2d3a7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_019cba81-e142-7b87-abf2-b758db5386d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_019cba81-e142-7b87-abf2-b758db5386d2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_019cba81-e142-7406-aaa9-93bf3914a540" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_019cba81-e142-7406-aaa9-93bf3914a540" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_019cba81-e142-70bd-85ad-3de77a10201d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019cba81-e142-7e01-bd07-a2f2a7e91d15" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_019cba81-e142-70bd-85ad-3de77a10201d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/LOANSANDLEASESScheduleofNonPerformingAssetsDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#LOANSANDLEASESScheduleofNonPerformingAssetsDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/LOANSANDLEASESScheduleofNonPerformingAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_fnb_FinancingReceivableNonPerformingLoansAndLeases_019cba81-e142-760e-bfbc-35d0e8120bd5" xlink:href="fnb-20260331.xsd#fnb_FinancingReceivableNonPerformingLoansAndLeases"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_019cba81-e142-7ee7-b30e-28ff07ef9987" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_FinancingReceivableNonPerformingLoansAndLeases_019cba81-e142-760e-bfbc-35d0e8120bd5" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_019cba81-e142-7ee7-b30e-28ff07ef9987" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_FinancingReceivableNonPerformingAssets_019cba81-e142-7e81-9a9a-0218d742b658" xlink:href="fnb-20260331.xsd#fnb_FinancingReceivableNonPerformingAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_FinancingReceivableNonPerformingLoansAndLeases_019cba81-e142-7db7-bc1b-11c2e6a700f2" xlink:href="fnb-20260331.xsd#fnb_FinancingReceivableNonPerformingLoansAndLeases"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_FinancingReceivableNonPerformingAssets_019cba81-e142-7e81-9a9a-0218d742b658" xlink:to="loc_fnb_FinancingReceivableNonPerformingLoansAndLeases_019cba81-e142-7db7-bc1b-11c2e6a700f2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAcquiredThroughForeclosure_019cba81-e142-7895-bff2-c940bd806fda" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealEstateAcquiredThroughForeclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_FinancingReceivableNonPerformingAssets_019cba81-e142-7e81-9a9a-0218d742b658" xlink:to="loc_us-gaap_RealEstateAcquiredThroughForeclosure_019cba81-e142-7895-bff2-c940bd806fda" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/ALLOWANCEFORCREDITLOSSESONLOANSANDLEASESScheduleofChangesinAllowanceforCreditLossesDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#ALLOWANCEFORCREDITLOSSESONLOANSANDLEASESScheduleofChangesinAllowanceforCreditLossesDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/ALLOWANCEFORCREDITLOSSESONLOANSANDLEASESScheduleofChangesinAllowanceforCreditLossesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019cba81-e143-755c-86d3-c5238799a2e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e143-7900-9631-fddbd6849536" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019cba81-e143-755c-86d3-c5238799a2e6" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_019cba81-e143-7900-9631-fddbd6849536" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_019cba81-e143-71d6-9961-e495f3e6313e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery_019cba81-e143-755c-86d3-c5238799a2e6" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_019cba81-e143-71d6-9961-e495f3e6313e" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/LEASESScheduleofLeaseExpenseDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#LEASESScheduleofLeaseExpenseDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/LEASESScheduleofLeaseExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost_019cba81-e143-7b1d-91b1-2eeac0592940" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseCost"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost_019cba81-e143-7e7e-92b1-ba73a1d71ef5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019cba81-e143-7b1d-91b1-2eeac0592940" xlink:to="loc_us-gaap_OperatingLeaseCost_019cba81-e143-7e7e-92b1-ba73a1d71ef5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableLeaseCost_019d241a-9862-71a7-966b-5b1a0c2f5d2e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableLeaseCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019cba81-e143-7b1d-91b1-2eeac0592940" xlink:to="loc_us-gaap_VariableLeaseCost_019d241a-9862-71a7-966b-5b1a0c2f5d2e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_FinanceLeaseCost_019cba81-e143-7a94-aea0-00f1c07c4ddd" xlink:href="fnb-20260331.xsd#fnb_FinanceLeaseCost"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019cba81-e143-7b1d-91b1-2eeac0592940" xlink:to="loc_fnb_FinanceLeaseCost_019cba81-e143-7a94-aea0-00f1c07c4ddd" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-76e2-bea6-d2b7b92105ec" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaid"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7faa-aae6-cff3faefee7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-76e2-bea6-d2b7b92105ec" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7faa-aae6-cff3faefee7b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-714c-99a1-841b0fdc6f36" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-76e2-bea6-d2b7b92105ec" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-714c-99a1-841b0fdc6f36" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidAfterRollingYearFive_019cba81-e143-7f16-8ab9-b253a7fc7785" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidAfterRollingYearFive"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive_019cba81-e143-7664-baa4-c5cf4d1ccbbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidAfterRollingYearFive_019cba81-e143-7f16-8ab9-b253a7fc7785" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive_019cba81-e143-7664-baa4-c5cf4d1ccbbd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive_019cba81-e143-7a86-a16a-c123802efbbb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidAfterRollingYearFive_019cba81-e143-7f16-8ab9-b253a7fc7785" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive_019cba81-e143-7a86-a16a-c123802efbbb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiability_019cba81-e143-7df0-bac8-5a47b53cf8f0" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiability"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_019cba81-e143-7b41-9a82-730b6e7e0f31" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiability_019cba81-e143-7df0-bac8-5a47b53cf8f0" xlink:to="loc_us-gaap_FinanceLeaseLiability_019cba81-e143-7b41-9a82-730b6e7e0f31" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_019cba81-e143-7799-b3c7-8e424d1f9945" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiability_019cba81-e143-7df0-bac8-5a47b53cf8f0" xlink:to="loc_us-gaap_OperatingLeaseLiability_019cba81-e143-7799-b3c7-8e424d1f9945" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7b84-8c7b-d73bb73a24e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7224-9867-23cf2320670e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7b84-8c7b-d73bb73a24e3" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7224-9867-23cf2320670e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_019cba81-e143-7060-8b55-1e1eb5a784c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7b84-8c7b-d73bb73a24e3" xlink:to="loc_us-gaap_OperatingLeaseLiability_019cba81-e143-7060-8b55-1e1eb5a784c2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-774c-bb13-9b92558b0830" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiability_019cba81-e143-7428-b390-1e3334efe27a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-774c-bb13-9b92558b0830" xlink:to="loc_us-gaap_FinanceLeaseLiability_019cba81-e143-7428-b390-1e3334efe27a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7b27-88e5-0c38639a83f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-774c-bb13-9b92558b0830" xlink:to="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7b27-88e5-0c38639a83f8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFive_019cba81-e143-7275-b682-2b3987f95289" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFive"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-715c-8d44-08cc1509cb68" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFive_019cba81-e143-7275-b682-2b3987f95289" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-715c-8d44-08cc1509cb68" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-7dca-93fb-91e8503284a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFive_019cba81-e143-7275-b682-2b3987f95289" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-7dca-93fb-91e8503284a5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7830-978c-3a6c02174805" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7890-9a5e-0e0da5e64b9b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7830-978c-3a6c02174805" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7890-9a5e-0e0da5e64b9b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7109-9598-1d6217c46b7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7830-978c-3a6c02174805" xlink:to="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7109-9598-1d6217c46b7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearTwo_019cba81-e143-7caf-ac4b-4da0fd8f0b7f" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearTwo"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-73ee-bec6-6c60dae2bd59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearTwo_019cba81-e143-7caf-ac4b-4da0fd8f0b7f" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-73ee-bec6-6c60dae2bd59" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-7040-bfb6-d493e292b49a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearTwo_019cba81-e143-7caf-ac4b-4da0fd8f0b7f" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-7040-bfb6-d493e292b49a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidNextRolling12Months_019cba81-e143-722e-8848-d600fa9af25a" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidNextRolling12Months"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths_019cba81-e143-7526-8cc0-475800554a95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidNextRolling12Months_019cba81-e143-722e-8848-d600fa9af25a" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths_019cba81-e143-7526-8cc0-475800554a95" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths_019cba81-e143-7e90-b391-485a8b2d90ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidNextRolling12Months_019cba81-e143-722e-8848-d600fa9af25a" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths_019cba81-e143-7e90-b391-485a8b2d90ae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearThree_019cba81-e143-7a49-a478-e04319341b59" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearThree"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-76f5-9d8f-ce301d15e59d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearThree_019cba81-e143-7a49-a478-e04319341b59" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-76f5-9d8f-ce301d15e59d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-7387-b942-9f9407ca7218" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearThree_019cba81-e143-7a49-a478-e04319341b59" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-7387-b942-9f9407ca7218" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFour_019cba81-e143-7b6a-8063-cf98b8291a71" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFour"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7a0a-8f30-e7042f72be82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFour_019cba81-e143-7b6a-8063-cf98b8291a71" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7a0a-8f30-e7042f72be82" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7d22-bbc3-cb2576a77f69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFour_019cba81-e143-7b6a-8063-cf98b8291a71" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7d22-bbc3-cb2576a77f69" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails_1" xlink:type="simple" xlink:href="fnb-20260331.xsd#LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails_1"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7530-a488-80b334e83044" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive_019cba81-e143-7e37-83d1-35b2eafba283" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7530-a488-80b334e83044" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterRollingYearFive_019cba81-e143-7e37-83d1-35b2eafba283" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-70e5-9281-2b5696a52d6c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7530-a488-80b334e83044" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-70e5-9281-2b5696a52d6c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7e86-9149-8f574935d92a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7530-a488-80b334e83044" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7e86-9149-8f574935d92a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-79d5-856b-26d924a4f089" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7530-a488-80b334e83044" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-79d5-856b-26d924a4f089" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths_019cba81-e143-7de1-9a0a-acc082a0c1c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7530-a488-80b334e83044" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextRollingTwelveMonths_019cba81-e143-7de1-9a0a-acc082a0c1c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-7b7e-8eee-fcc021b14b79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019cba81-e143-7530-a488-80b334e83044" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-7b7e-8eee-fcc021b14b79" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7e8a-8a31-64430985b40d" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaid"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7a1a-a45c-95f83b0d5ea4" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7e8a-8a31-64430985b40d" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount_019cba81-e143-7a1a-a45c-95f83b0d5ea4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiability_019cba81-e143-7d85-9d63-ea31e34cd618" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7e8a-8a31-64430985b40d" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiability_019cba81-e143-7d85-9d63-ea31e34cd618" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-77ae-bd0c-5c5b44b3a818" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive_019cba81-e143-70d0-bfd5-034202cc36bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-77ae-bd0c-5c5b44b3a818" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingAfterYearFive_019cba81-e143-70d0-bfd5-034202cc36bc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-7579-98d3-99c3f7dda951" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-77ae-bd0c-5c5b44b3a818" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearTwo_019cba81-e143-7579-98d3-99c3f7dda951" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-73ac-9478-af7cce871468" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-77ae-bd0c-5c5b44b3a818" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFive_019cba81-e143-73ac-9478-af7cce871468" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7f38-b103-6a0e768050d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-77ae-bd0c-5c5b44b3a818" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearFour_019cba81-e143-7f38-b103-6a0e768050d7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths_019cba81-e143-7942-ac5e-7fb42118bb43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-77ae-bd0c-5c5b44b3a818" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInNextRollingTwelveMonths_019cba81-e143-7942-ac5e-7fb42118bb43" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-78d0-bb99-c60a15adc75e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019cba81-e143-77ae-bd0c-5c5b44b3a818" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueInRollingYearThree_019cba81-e143-78d0-bb99-c60a15adc75e" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails_2" xlink:type="simple" xlink:href="fnb-20260331.xsd#LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails_2"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/LEASESScheduleofFutureCashFlowofLeaseLiabilitiesDetails_2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7576-88d6-0efea46e59c8" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaid"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFive_019cba81-e143-7fc9-905d-a38d2c712f80" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFive"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7576-88d6-0efea46e59c8" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFive_019cba81-e143-7fc9-905d-a38d2c712f80" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearTwo_019cba81-e143-74c9-a2e7-8260048e9ad3" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearTwo"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7576-88d6-0efea46e59c8" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearTwo_019cba81-e143-74c9-a2e7-8260048e9ad3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearThree_019cba81-e143-7ee7-a66c-26621b4863ff" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearThree"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7576-88d6-0efea46e59c8" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearThree_019cba81-e143-7ee7-a66c-26621b4863ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidNextRolling12Months_019cba81-e143-7ebf-ad17-9cd158f044e8" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidNextRolling12Months"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7576-88d6-0efea46e59c8" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidNextRolling12Months_019cba81-e143-7ebf-ad17-9cd158f044e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidAfterRollingYearFive_019cba81-e143-7015-aa5c-74ccbe4fa452" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidAfterRollingYearFive"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7576-88d6-0efea46e59c8" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidAfterRollingYearFive_019cba81-e143-7015-aa5c-74ccbe4fa452" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFour_019cba81-e143-7b32-bdff-165c6a98b3eb" xlink:href="fnb-20260331.xsd#fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFour"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaid_019cba81-e143-7576-88d6-0efea46e59c8" xlink:to="loc_fnb_OperatingAndFinanceLeaseLiabilityToBePaidRollingYearFour_019cba81-e143-7b32-bdff-165c6a98b3eb" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/VARIABLEINTERESTENTITIESScheduleofImpactofTaxCreditInvestmentsonProvisionforIncomeTaxesDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#VARIABLEINTERESTENTITIESScheduleofImpactofTaxCreditInvestmentsonProvisionforIncomeTaxesDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/VARIABLEINTERESTENTITIESScheduleofImpactofTaxCreditInvestmentsonProvisionforIncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromAffordableHousingProjectsEquityMethodInvestments_019cba81-e1e7-7d9c-aef4-c0bcadacfd4c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromAffordableHousingProjectsEquityMethodInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization_019cba81-e1e7-75d4-bc53-d81af9aeffa5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromAffordableHousingProjectsEquityMethodInvestments_019cba81-e1e7-7d9c-aef4-c0bcadacfd4c" xlink:to="loc_us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization_019cba81-e1e7-75d4-bc53-d81af9aeffa5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit_019cba81-e1e7-727e-9446-68fc8baf2a11" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromAffordableHousingProjectsEquityMethodInvestments_019cba81-e1e7-7d9c-aef4-c0bcadacfd4c" xlink:to="loc_us-gaap_InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit_019cba81-e1e7-727e-9446-68fc8baf2a11" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentProgramProportionalAmortizationMethodElectedOtherIncomeTaxBenefit_019cba81-e1e7-7463-a723-26db236ba587" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentProgramProportionalAmortizationMethodElectedOtherIncomeTaxBenefit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromAffordableHousingProjectsEquityMethodInvestments_019cba81-e1e7-7d9c-aef4-c0bcadacfd4c" xlink:to="loc_us-gaap_InvestmentProgramProportionalAmortizationMethodElectedOtherIncomeTaxBenefit_019cba81-e1e7-7463-a723-26db236ba587" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/DEPOSITSScheduleofDepositsDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#DEPOSITSScheduleofDepositsDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/DEPOSITSScheduleofDepositsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_019d6792-e1b3-7a19-95d1-8296d81fd06c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Deposits"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDepositLiabilities_019d6792-e1b3-7061-ab54-e0575c1ebb16" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestBearingDepositLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d6792-e1b3-7a19-95d1-8296d81fd06c" xlink:to="loc_us-gaap_NoninterestBearingDepositLiabilities_019d6792-e1b3-7061-ab54-e0575c1ebb16" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDomesticDepositDemand_019d6792-e1b3-70b8-b8c3-17e3663498e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestBearingDomesticDepositDemand"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d6792-e1b3-7a19-95d1-8296d81fd06c" xlink:to="loc_us-gaap_InterestBearingDomesticDepositDemand_019d6792-e1b3-70b8-b8c3-17e3663498e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsMoneyMarketDeposits_019d679a-e66c-76db-97af-240f95997cf8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositsMoneyMarketDeposits"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d6792-e1b3-7a19-95d1-8296d81fd06c" xlink:to="loc_us-gaap_DepositsMoneyMarketDeposits_019d679a-e66c-76db-97af-240f95997cf8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsSavingsDeposits_019d6792-e1b3-771b-827d-17f271d5df44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositsSavingsDeposits"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d6792-e1b3-7a19-95d1-8296d81fd06c" xlink:to="loc_us-gaap_DepositsSavingsDeposits_019d6792-e1b3-771b-827d-17f271d5df44" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDeposits_019d6792-e1b3-776b-a4b3-75982a2cec26" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimeDeposits"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d6792-e1b3-7a19-95d1-8296d81fd06c" xlink:to="loc_us-gaap_TimeDeposits_019d6792-e1b3-776b-a4b3-75982a2cec26" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/BORROWINGSScheduleofShortTermBorrowingsDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#BORROWINGSScheduleofShortTermBorrowingsDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/BORROWINGSScheduleofShortTermBorrowingsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_019cba81-e1e7-72a6-badf-9f8a836de397" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermBorrowings"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate_019cba81-e1e7-7c4d-9f94-d214842e4863" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermBorrowings_019cba81-e1e7-72a6-badf-9f8a836de397" xlink:to="loc_us-gaap_FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate_019cba81-e1e7-7c4d-9f94-d214842e4863" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalFundsPurchased_019cba81-e1e7-7388-8d35-e06a191d4304" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalFundsPurchased"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermBorrowings_019cba81-e1e7-72a6-badf-9f8a836de397" xlink:to="loc_us-gaap_FederalFundsPurchased_019cba81-e1e7-7388-8d35-e06a191d4304" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_019cba81-e1e7-78b9-849a-41f48ae163db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermBorrowings_019cba81-e1e7-72a6-badf-9f8a836de397" xlink:to="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_019cba81-e1e7-78b9-849a-41f48ae163db" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_SubordinatedNotesShortTerm_019cba81-e1e7-7a13-80a6-b393f29e67b1" xlink:href="fnb-20260331.xsd#fnb_SubordinatedNotesShortTerm"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ShortTermBorrowings_019cba81-e1e7-72a6-badf-9f8a836de397" xlink:to="loc_fnb_SubordinatedNotesShortTerm_019cba81-e1e7-7a13-80a6-b393f29e67b1" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/BORROWINGSScheduleofLongTermBorrowingsDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#BORROWINGSScheduleofLongTermBorrowingsDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/BORROWINGSScheduleofLongTermBorrowingsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019cba81-e1e7-7542-bb5c-6af6efc25850" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotes_019cba81-e1e7-78b6-8cb7-1856a2c6f5c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SeniorNotes"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019cba81-e1e7-7542-bb5c-6af6efc25850" xlink:to="loc_us-gaap_SeniorNotes_019cba81-e1e7-78b6-8cb7-1856a2c6f5c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedLongTermDebt_019cba81-e1e7-776a-9e1c-3f66ebc4b649" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubordinatedLongTermDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019cba81-e1e7-7542-bb5c-6af6efc25850" xlink:to="loc_us-gaap_SubordinatedLongTermDebt_019cba81-e1e7-776a-9e1c-3f66ebc4b649" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLongTermDebt_019cba81-e1e7-74e9-a294-69edc2fdb616" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLongTermDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019cba81-e1e7-7542-bb5c-6af6efc25850" xlink:to="loc_us-gaap_OtherLongTermDebt_019cba81-e1e7-74e9-a294-69edc2fdb616" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankAdvancesLongTerm_019cba81-e1e7-7914-b552-244fa5d5102d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FederalHomeLoanBankAdvancesLongTerm"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019cba81-e1e7-7542-bb5c-6af6efc25850" xlink:to="loc_us-gaap_FederalHomeLoanBankAdvancesLongTerm_019cba81-e1e7-7914-b552-244fa5d5102d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_019cba81-e1e7-7a2c-a05e-87eb7d844f1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_019cba81-e1e7-7542-bb5c-6af6efc25850" xlink:to="loc_us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust_019cba81-e1e7-7a2c-a05e-87eb7d844f1d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofNotionalAmountsandGrossFairValuesDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofNotionalAmountsandGrossFairValuesDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofNotionalAmountsandGrossFairValuesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019cba81-e1e7-79e2-89fc-d99cb14b3c6a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7afe-96ae-e1989750cf1a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssets_019cba81-e1e7-79e2-89fc-d99cb14b3c6a" xlink:to="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7afe-96ae-e1989750cf1a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotSubjectToMasterNettingArrangement_019cba81-e1e7-78db-b016-c9ab4b43e0bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetNotSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssets_019cba81-e1e7-79e2-89fc-d99cb14b3c6a" xlink:to="loc_us-gaap_DerivativeAssetNotSubjectToMasterNettingArrangement_019cba81-e1e7-78db-b016-c9ab4b43e0bb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7cb6-a772-601f404364c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7900-97fb-85353a56af7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7cb6-a772-601f404364c1" xlink:to="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7900-97fb-85353a56af7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotSubjectToMasterNettingArrangement_019cba81-e1e7-7bc2-9f92-901258d99bdc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityNotSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7cb6-a772-601f404364c1" xlink:to="loc_us-gaap_DerivativeLiabilityNotSubjectToMasterNettingArrangement_019cba81-e1e7-7bc2-9f92-901258d99bdc" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofDerivativeAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofDerivativeAssetsandLiabilitiesDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofDerivativeAssetsandLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7120-aa90-16760a1f824b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueGrossAsset_019cba81-e1e7-72e8-97a8-bbfc4b8c2364" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityFairValueGrossAsset"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7120-aa90-16760a1f824b" xlink:to="loc_us-gaap_DerivativeLiabilityFairValueGrossAsset_019cba81-e1e7-72e8-97a8-bbfc4b8c2364" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7966-9aeb-dff3172dd9e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7120-aa90-16760a1f824b" xlink:to="loc_us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7966-9aeb-dff3172dd9e3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7770-b1fc-566842b84085" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotSubjectToMasterNettingArrangement_019cba81-e1e7-7701-a6a0-0400f60a27b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityNotSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7770-b1fc-566842b84085" xlink:to="loc_us-gaap_DerivativeLiabilityNotSubjectToMasterNettingArrangement_019cba81-e1e7-7701-a6a0-0400f60a27b8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_019cba81-e1e7-7524-9a22-3dd811ca2098" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7770-b1fc-566842b84085" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_019cba81-e1e7-7524-9a22-3dd811ca2098" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7c9f-acf2-d3eb3e4debec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCollateralRightToReclaimCash_019cba81-e1e7-72ef-99d0-ae3928c2ef29" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeCollateralRightToReclaimCash"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7c9f-acf2-d3eb3e4debec" xlink:to="loc_us-gaap_DerivativeCollateralRightToReclaimCash_019cba81-e1e7-72ef-99d0-ae3928c2ef29" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_019cba81-e1e7-756b-87a5-dc9b0bf4dd09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7c9f-acf2-d3eb3e4debec" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_019cba81-e1e7-756b-87a5-dc9b0bf4dd09" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction_019cba81-e1e7-7b7b-9b5e-43c4ed1e149f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7c9f-acf2-d3eb3e4debec" xlink:to="loc_us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction_019cba81-e1e7-7b7b-9b5e-43c4ed1e149f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-717d-a1f7-a2c22d294316" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_019cba81-e1e7-7d41-9dfd-9134af767ee8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-717d-a1f7-a2c22d294316" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_019cba81-e1e7-7d41-9dfd-9134af767ee8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueGrossLiability_019cba81-e1e7-73e3-a543-31daa431adc2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetFairValueGrossLiability"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-717d-a1f7-a2c22d294316" xlink:to="loc_us-gaap_DerivativeAssetFairValueGrossLiability_019cba81-e1e7-73e3-a543-31daa431adc2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-737e-8e87-068f05d1575f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction_019cba81-e1e7-7e58-9a60-0cca7060a05d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-737e-8e87-068f05d1575f" xlink:to="loc_us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction_019cba81-e1e7-7e58-9a60-0cca7060a05d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_019cba81-e1e7-74c8-b0cc-20939e35bf63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-737e-8e87-068f05d1575f" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_019cba81-e1e7-74c8-b0cc-20939e35bf63" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019cba81-e1e7-7e09-b1da-06eede1edbd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeCollateralObligationToReturnCash"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-737e-8e87-068f05d1575f" xlink:to="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019cba81-e1e7-7e09-b1da-06eede1edbd3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-747c-99cb-4312ed573f8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueGrossAsset_019cba81-e1e7-78e1-a375-f9296f2ce19c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityFairValueGrossAsset"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-747c-99cb-4312ed573f8f" xlink:to="loc_us-gaap_DerivativeLiabilityFairValueGrossAsset_019cba81-e1e7-78e1-a375-f9296f2ce19c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_019cba81-e1e7-7e50-86e3-742d915c527b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-747c-99cb-4312ed573f8f" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_019cba81-e1e7-7e50-86e3-742d915c527b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7676-871f-5834bf423ae0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_019cba81-e1e7-7ed9-a3e6-5ec3523803a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7676-871f-5834bf423ae0" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_019cba81-e1e7-7ed9-a3e6-5ec3523803a8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotSubjectToMasterNettingArrangement_019cba81-e1e7-754f-9a31-6ca7f4f097bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetNotSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement_019cba81-e1e7-7676-871f-5834bf423ae0" xlink:to="loc_us-gaap_DerivativeAssetNotSubjectToMasterNettingArrangement_019cba81-e1e7-754f-9a31-6ca7f4f097bd" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofDerivativeAssetsandLiabilitiesDetails_1" xlink:type="simple" xlink:href="fnb-20260331.xsd#DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofDerivativeAssetsandLiabilitiesDetails_1"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/DERIVATIVEINSTRUMENTSANDHEDGINGACTIVITIESScheduleofDerivativeAssetsandLiabilitiesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-76ec-b9c6-dbcadcf4c710" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCollateralRightToReclaimCash_019cba81-e1e7-726e-913b-f59392857368" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeCollateralRightToReclaimCash"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-76ec-b9c6-dbcadcf4c710" xlink:to="loc_us-gaap_DerivativeCollateralRightToReclaimCash_019cba81-e1e7-726e-913b-f59392857368" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7bee-b9e4-2c4ca3403142" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-76ec-b9c6-dbcadcf4c710" xlink:to="loc_us-gaap_DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7bee-b9e4-2c4ca3403142" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction_019cba81-e1e7-78e3-a314-3b8d2a2edcde" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-76ec-b9c6-dbcadcf4c710" xlink:to="loc_us-gaap_DerivativeLiabilityNotOffsetPolicyElectionDeduction_019cba81-e1e7-78e3-a314-3b8d2a2edcde" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7a2c-b5f2-e9a9eb78a845" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction_019cba81-e1e7-7092-b74f-cff3dbe69d4a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7a2c-b5f2-e9a9eb78a845" xlink:to="loc_us-gaap_DerivativeAssetNotOffsetPolicyElectionDeduction_019cba81-e1e7-7092-b74f-cff3dbe69d4a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019cba81-e1e7-7494-b787-b2be4d798e08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeCollateralObligationToReturnCash"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7a2c-b5f2-e9a9eb78a845" xlink:to="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019cba81-e1e7-7494-b787-b2be4d798e08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7b0f-aad6-d4b52e3db32f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DerivativeAssetFairValueAfterOffsetAndDeductionSubjectToMasterNettingArrangement_019cba81-e1e7-7a2c-b5f2-e9a9eb78a845" xlink:to="loc_us-gaap_DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement_019cba81-e1e7-7b0f-aad6-d4b52e3db32f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/INCOMETAXESScheduleofIncomeTaxExpenseDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#INCOMETAXESScheduleofIncomeTaxExpenseDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/INCOMETAXESScheduleofIncomeTaxExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019cba81-e1e7-7e63-9f95-dc48713630cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_019cba81-e1e7-7c8b-bb40-121c0662f5f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019cba81-e1e7-7e63-9f95-dc48713630cd" xlink:to="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_019cba81-e1e7-7c8b-bb40-121c0662f5f4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019cba81-e1e7-78b3-85b7-c2d1369d27e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019cba81-e1e7-7e63-9f95-dc48713630cd" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019cba81-e1e7-78b3-85b7-c2d1369d27e7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_019cba81-e1e7-75eb-a991-0dc83745cb44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentFederalTaxExpenseBenefit_019cba81-e1e7-7137-ac13-5434247e4068" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentFederalTaxExpenseBenefit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_019cba81-e1e7-75eb-a991-0dc83745cb44" xlink:to="loc_us-gaap_CurrentFederalTaxExpenseBenefit_019cba81-e1e7-7137-ac13-5434247e4068" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_019cba81-e1e7-7b3b-b8a2-42fe8bd11c1a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CurrentIncomeTaxExpenseBenefit_019cba81-e1e7-75eb-a991-0dc83745cb44" xlink:to="loc_us-gaap_CurrentStateAndLocalTaxExpenseBenefit_019cba81-e1e7-7b3b-b8a2-42fe8bd11c1a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019cba81-e1e7-7438-981a-0af166928366" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_019cba81-e1e7-7dcb-8129-255ee4d34260" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019cba81-e1e7-7438-981a-0af166928366" xlink:to="loc_us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_019cba81-e1e7-7dcb-8129-255ee4d34260" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_019cba81-e1e7-7cd4-9dd5-2914ec2befed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019cba81-e1e7-7438-981a-0af166928366" xlink:to="loc_us-gaap_DeferredFederalIncomeTaxExpenseBenefit_019cba81-e1e7-7cd4-9dd5-2914ec2befed" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/OTHERCOMPREHENSIVEINCOMELOSSDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#OTHERCOMPREHENSIVEINCOMELOSSDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/OTHERCOMPREHENSIVEINCOMELOSSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e1e7-71fc-9ea4-8670795f7a54" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019cba81-e1e7-70f4-bb20-850efd8dc8e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019cba81-e1e7-71fc-9ea4-8670795f7a54" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019cba81-e1e7-70f4-bb20-850efd8dc8e6" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/EARNINGSPERCOMMONSHAREDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#EARNINGSPERCOMMONSHAREDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/EARNINGSPERCOMMONSHAREDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019cba81-e1e7-7de2-bae4-3905f130bdca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019cba81-e1e7-770b-8ae0-069b0064f8ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019cba81-e1e7-7de2-bae4-3905f130bdca" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019cba81-e1e7-770b-8ae0-069b0064f8ff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_019cba81-e1e7-74b3-98a7-e650b2bd48c7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019cba81-e1e7-7de2-bae4-3905f130bdca" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_019cba81-e1e7-74b3-98a7-e650b2bd48c7" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/BUSINESSSEGMENTSScheduleofFinancialInformationforSegmentsofFNBDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#BUSINESSSEGMENTSScheduleofFinancialInformationforSegmentsofFNBDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/BUSINESSSEGMENTSScheduleofFinancialInformationforSegmentsofFNBDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_ServiceCharges_019cba81-e1e7-7f47-ae22-7c8d2ddbf495" xlink:href="fnb-20260331.xsd#fnb_ServiceCharges"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_fnb_ServiceCharges_019cba81-e1e7-7f47-ae22-7c8d2ddbf495" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_TrustServices_019cba81-e1e7-79cc-9583-505b28ab877f" xlink:href="fnb-20260331.xsd#fnb_TrustServices"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_fnb_TrustServices_019cba81-e1e7-79cc-9583-505b28ab877f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_InterchangeAndCardTransactionFees_019cba81-e1e7-7ad1-b720-9190951da282" xlink:href="fnb-20260331.xsd#fnb_InterchangeAndCardTransactionFees"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_fnb_InterchangeAndCardTransactionFees_019cba81-e1e7-7ad1-b720-9190951da282" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_NoninterestIncomeMiscellaneous_019cba81-e1e7-78de-99f8-ce30885224da" xlink:href="fnb-20260331.xsd#fnb_NoninterestIncomeMiscellaneous"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_fnb_NoninterestIncomeMiscellaneous_019cba81-e1e7-78de-99f8-ce30885224da" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InsuranceCommissionsAndFees_019cba81-e1e7-7a76-9d90-1af0f07a3149" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InsuranceCommissionsAndFees"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_us-gaap_InsuranceCommissionsAndFees_019cba81-e1e7-7a76-9d90-1af0f07a3149" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_CapitalMarketsIncome_019cba81-e1e7-7856-971e-00d50e7f3703" xlink:href="fnb-20260331.xsd#fnb_CapitalMarketsIncome"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_fnb_CapitalMarketsIncome_019cba81-e1e7-7856-971e-00d50e7f3703" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_MortgageBankingOperatingIncome_019cba81-e1e7-78a9-97a3-04231e6d8528" xlink:href="fnb-20260331.xsd#fnb_MortgageBankingOperatingIncome"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_fnb_MortgageBankingOperatingIncome_019cba81-e1e7-78a9-97a3-04231e6d8528" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions_019cba81-e1e7-702c-bdfb-c5dcecf12ece" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019cba81-e1e7-7a47-84e0-9c62f329f6ae" xlink:to="loc_us-gaap_InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions_019cba81-e1e7-702c-bdfb-c5dcecf12ece" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_019cba81-e1e7-7328-81a6-98e026c942a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_fnb_NoninterestExpenseMiscellaneous_019cba81-e1e7-79ab-9ab0-b8e648dcb553" xlink:href="fnb-20260331.xsd#fnb_NoninterestExpenseMiscellaneous"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e1e7-7328-81a6-98e026c942a2" xlink:to="loc_fnb_NoninterestExpenseMiscellaneous_019cba81-e1e7-79ab-9ab0-b8e648dcb553" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019cba81-e1e7-7115-97e1-673149c6427f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019cba81-e1e7-7328-81a6-98e026c942a2" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019cba81-e1e7-7115-97e1-673149c6427f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fnb-online.com/role/FAIRVALUEMEASUREMENTSScheduleofAssetsandLiabilitiesonRecurringBasisDetails" xlink:type="simple" xlink:href="fnb-20260331.xsd#FAIRVALUEMEASUREMENTSScheduleofAssetsandLiabilitiesonRecurringBasisDetails"/>
  <link:calculationLink xlink:role="http://www.fnb-online.com/role/FAIRVALUEMEASUREMENTSScheduleofAssetsandLiabilitiesonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019cba81-e1e7-7a15-9f9e-78f30412b7cc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019cba81-e1e7-763d-a898-6904e5cf543a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeAssets"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019cba81-e1e7-7a15-9f9e-78f30412b7cc" xlink:to="loc_us-gaap_DerivativeAssets_019cba81-e1e7-763d-a898-6904e5cf543a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansHeldForSaleFairValueDisclosure_019cba81-e1e7-7558-8f7a-ce0c3f0d9766" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansHeldForSaleFairValueDisclosure"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019cba81-e1e7-7a15-9f9e-78f30412b7cc" xlink:to="loc_us-gaap_LoansHeldForSaleFairValueDisclosure_019cba81-e1e7-7558-8f7a-ce0c3f0d9766" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e1e7-7c72-998c-663a2024c8a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019cba81-e1e7-7a15-9f9e-78f30412b7cc" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019cba81-e1e7-7c72-998c-663a2024c8a4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableFairValueDisclosure_019cba81-e1e7-7822-9efc-dd16c4b289a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansReceivableFairValueDisclosure"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019cba81-e1e7-7a15-9f9e-78f30412b7cc" xlink:to="loc_us-gaap_LoansReceivableFairValueDisclosure_019cba81-e1e7-7822-9efc-dd16c4b289a9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialLiabilitiesFairValueDisclosure_019cba81-e1e7-7ddd-aa69-01fcc0369258" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialLiabilitiesFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7ec8-9e25-208d206fcd9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DerivativeLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancialLiabilitiesFairValueDisclosure_019cba81-e1e7-7ddd-aa69-01fcc0369258" xlink:to="loc_us-gaap_DerivativeLiabilities_019cba81-e1e7-7ec8-9e25-208d206fcd9a" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
