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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019d21a3-bad3-7e96-925a-6cac305ff299,g:2c6edfd1-3319-4050-b140-d27ece2aaa17-->
<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.coastalbank.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUNAUDITED" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#CONDENSEDCONSOLIDATEDBALANCESHEETSUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/CONDENSEDCONSOLIDATEDBALANCESHEETSUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" 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_OtherAssets_019d21a3-c13d-7d49-87a7-fc25c33cdd7b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssets"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_OtherAssets_019d21a3-c13d-7d49-87a7-fc25c33cdd7b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019d21a3-c13d-7fe3-b945-999bb84e72de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019d21a3-c13d-7fe3-b945-999bb84e72de" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositsInBanks_019d21a3-c13d-74ce-b3c5-880299d62282" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestBearingDepositsInBanks"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_InterestBearingDepositsInBanks_019d21a3-c13d-74ce-b3c5-880299d62282" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsurance_019d21a3-c13d-7bc4-9992-407a1e882dc1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BankOwnedLifeInsurance"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_BankOwnedLifeInsurance_019d21a3-c13d-7bc4-9992-407a1e882dc1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019d21a3-c13d-710f-b62e-3315d7358566" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019d21a3-c13d-710f-b62e-3315d7358566" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAtAmortizedCost_019d21a3-c13d-7fbe-be83-ea796671c544" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAtAmortizedCost"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_ck1437958_DebtSecuritiesHeldToMaturityExcludingAccruedInterestAtAmortizedCost_019d21a3-c13d-7fbe-be83-ea796671c544" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_CreditEnhancementAsset_019d21a3-c13d-7835-a38f-528414d3b979" xlink:href="ck1437958-20260331.xsd#ck1437958_CreditEnhancementAsset"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_ck1437958_CreditEnhancementAsset_019d21a3-c13d-7835-a38f-528414d3b979" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableHeldForSaleAmount_019d21a3-c13d-7e91-aa71-abbcdc8b3710" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansReceivableHeldForSaleAmount"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_LoansReceivableHeldForSaleAmount_019d21a3-c13d-7e91-aa71-abbcdc8b3710" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d21a3-c13d-7870-82c2-bbf6c276a166" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d21a3-c13d-7870-82c2-bbf6c276a166" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedInvestmentIncomeReceivable_019d21a3-c13d-70d2-bae4-ed02a8db7ea0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedInvestmentIncomeReceivable"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_AccruedInvestmentIncomeReceivable_019d21a3-c13d-70d2-bae4-ed02a8db7ea0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019d21a3-c13d-7987-b235-96eecf8398f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019d21a3-c13d-7987-b235-96eecf8398f9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndDueFromBanks_019d21a3-c13d-7d1f-b24f-463b6505fe23" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndDueFromBanks"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_CashAndDueFromBanks_019d21a3-c13d-7d1f-b24f-463b6505fe23" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivables_019d21a3-c13d-7d0f-8fc8-28375811bc39" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherReceivables"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_OtherReceivables_019d21a3-c13d-7d0f-8fc8-28375811bc39" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesOtherExcludingAccruedInterest_019d21a3-c13d-73f5-b19f-12d1e6fb873a" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesOtherExcludingAccruedInterest"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_ck1437958_DebtSecuritiesOtherExcludingAccruedInterest_019d21a3-c13d-73f5-b19f-12d1e6fb873a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_019de012-d187-7b65-91ce-9c2918f428d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d21a3-c13d-776e-afe2-9e66cc9c4eaa" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_019de012-d187-7b65-91ce-9c2918f428d2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019d21a3-c13d-7fb4-9623-0ba495a37887" 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_PreferredStockValue_019d21a3-c13d-71e4-8965-50c25ef06ba4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d21a3-c13d-7fb4-9623-0ba495a37887" xlink:to="loc_us-gaap_PreferredStockValue_019d21a3-c13d-71e4-8965-50c25ef06ba4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019d21a3-c13d-7785-b192-c8ba4eafc0cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d21a3-c13d-7fb4-9623-0ba495a37887" xlink:to="loc_us-gaap_CommonStockValue_019d21a3-c13d-7785-b192-c8ba4eafc0cd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d21a3-c13d-7a52-97c7-4c7b3463992f" 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_019d21a3-c13d-7fb4-9623-0ba495a37887" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d21a3-c13d-7a52-97c7-4c7b3463992f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019d21a3-c13d-7208-9e7e-0a2fb2942ab1" 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_019d21a3-c13d-7fb4-9623-0ba495a37887" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019d21a3-c13d-7208-9e7e-0a2fb2942ab1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" 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_019d21a3-c13d-7b31-a0c7-fcea73786ea6" 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_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_Deposits_019d21a3-c13d-7b31-a0c7-fcea73786ea6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebt_019d21a3-c13d-7f06-b600-84f36c66135c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubordinatedDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_SubordinatedDebt_019d21a3-c13d-7f06-b600-84f36c66135c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_JuniorSubordinatedNotes_019d21a3-c13d-7645-ae50-14eaf587a5db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_JuniorSubordinatedNotes"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_JuniorSubordinatedNotes_019d21a3-c13d-7645-ae50-14eaf587a5db" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent_019d21a3-c13d-7e27-ba36-3738e19156a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_DeferredCompensationLiabilityCurrentAndNoncurrent_019d21a3-c13d-7e27-ba36-3738e19156a0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPayableCurrentAndNoncurrent_019d21a3-c13d-7470-82a0-bea9ac70a007" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestPayableCurrentAndNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_InterestPayableCurrentAndNoncurrent_019d21a3-c13d-7470-82a0-bea9ac70a007" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019d21a3-c13d-766f-891b-9c9c12147a8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019d21a3-c13d-766f-891b-9c9c12147a8b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_019d21a3-c13d-7ca9-b048-8b774b01e508" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilities"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_OtherLiabilities_019d21a3-c13d-7ca9-b048-8b774b01e508" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrentAndNoncurrent_019d21a3-c13d-70e6-b6e5-7c9448bce1b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_AccountsPayableCurrentAndNoncurrent_019d21a3-c13d-70e6-b6e5-7c9448bce1b0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019d21a3-c13d-75fa-af8d-e106e4b47ea9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d21a3-c13d-7a39-b238-e3e8a31bf7fe" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019d21a3-c13d-75fa-af8d-e106e4b47ea9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d21a3-c13d-75ea-8194-6e057996e8b8" 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_019d21a3-c13d-7f57-8554-1a036ae39dce" 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_019d21a3-c13d-75ea-8194-6e057996e8b8" xlink:to="loc_us-gaap_Liabilities_019d21a3-c13d-7f57-8554-1a036ae39dce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019d21a3-c13d-7b51-8089-45942dfef7a1" 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_019d21a3-c13d-75ea-8194-6e057996e8b8" xlink:to="loc_us-gaap_StockholdersEquity_019d21a3-c13d-7b51-8089-45942dfef7a1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_019d21a3-c13d-7269-bf95-b5e85b469d33" 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_019d21a3-c13d-7f41-9434-d44c94b93c0b" 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_019d21a3-c13d-7269-bf95-b5e85b469d33" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-7f41-9434-d44c94b93c0b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019d21a3-c13d-7db8-9ab0-e44ff1f71081" 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_019d21a3-c13d-7269-bf95-b5e85b469d33" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_019d21a3-c13d-7db8-9ab0-e44ff1f71081" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:href="ck1437958-20260331.xsd#ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019d21a3-c13d-7723-9c07-eeff0767a2dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019d21a3-c13d-7723-9c07-eeff0767a2dc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_019d21a3-c13d-7646-94db-51bf3d649848" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OccupancyNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_us-gaap_OccupancyNet_019d21a3-c13d-7646-94db-51bf3d649848" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_SoftwareLicensesMaintenanceAndSubscriptions_019d21a3-c13d-715a-a925-044f04dc3be7" xlink:href="ck1437958-20260331.xsd#ck1437958_SoftwareLicensesMaintenanceAndSubscriptions"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_ck1437958_SoftwareLicensesMaintenanceAndSubscriptions_019d21a3-c13d-715a-a925-044f04dc3be7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_019d21a3-c13d-74ce-baaf-27ddec02cc90" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfessionalFees"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_us-gaap_ProfessionalFees_019d21a3-c13d-74ce-baaf-27ddec02cc90" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InformationTechnologyAndDataProcessing_019d21a3-c13d-7249-813b-76674755ee7d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InformationTechnologyAndDataProcessing"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_us-gaap_InformationTechnologyAndDataProcessing_019d21a3-c13d-7249-813b-76674755ee7d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_ExciseAndSalesTaxesCollected_019d21a3-c13d-7ded-b377-7470b241cdc8" xlink:href="ck1437958-20260331.xsd#ck1437958_ExciseAndSalesTaxesCollected"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_ck1437958_ExciseAndSalesTaxesCollected_019d21a3-c13d-7ded-b377-7470b241cdc8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_FederalDepositInsuranceCorporationPremiumExpenseBenefit_019d21a3-c13d-7be7-b4a3-f46516c9b1e8" xlink:href="ck1437958-20260331.xsd#ck1437958_FederalDepositInsuranceCorporationPremiumExpenseBenefit"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_ck1437958_FederalDepositInsuranceCorporationPremiumExpenseBenefit_019d21a3-c13d-7be7-b4a3-f46516c9b1e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_NoninterestDirectorsAndStaffExpenses_019d21a3-c13d-7e84-80e9-e9ba2b9312db" xlink:href="ck1437958-20260331.xsd#ck1437958_NoninterestDirectorsAndStaffExpenses"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_ck1437958_NoninterestDirectorsAndStaffExpenses_019d21a3-c13d-7e84-80e9-e9ba2b9312db" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketingExpense_019d21a3-c13d-7462-a94a-e6633dadd682" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MarketingExpense"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_us-gaap_MarketingExpense_019d21a3-c13d-7462-a94a-e6633dadd682" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_019d21a3-c13d-78d9-adab-13736235a6f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-7fea-8ac2-59843de7f5ff" xlink:to="loc_us-gaap_OtherNoninterestExpense_019d21a3-c13d-78d9-adab-13736235a6f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_019d21a3-c13d-7437-8d73-d773f9efcc36" 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_019d21a3-c13d-7197-8922-79454fc998a6" 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_019d21a3-c13d-7437-8d73-d773f9efcc36" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_019d21a3-c13d-7197-8922-79454fc998a6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_019d21a3-c13d-7f9c-8511-2d92379e2d8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_019d21a3-c13d-7437-8d73-d773f9efcc36" xlink:to="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_019d21a3-c13d-7f9c-8511-2d92379e2d8d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome_019d21a3-c13d-73bf-9ff5-850cd17a6880" xlink:href="ck1437958-20260331.xsd#ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DepositServiceChargesAndFees_019d21a3-c13d-7876-9e16-25bca2c188f1" xlink:href="ck1437958-20260331.xsd#ck1437958_DepositServiceChargesAndFees"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome_019d21a3-c13d-73bf-9ff5-850cd17a6880" xlink:to="loc_ck1437958_DepositServiceChargesAndFees_019d21a3-c13d-7876-9e16-25bca2c188f1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeOther_019d21a3-c13d-7644-a156-09e979ff5e87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestIncomeOther"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome_019d21a3-c13d-73bf-9ff5-850cd17a6880" xlink:to="loc_us-gaap_NoninterestIncomeOther_019d21a3-c13d-7644-a156-09e979ff5e87" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d21a3-c13d-7247-9e94-5f2916e2208f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome_019d21a3-c13d-73bf-9ff5-850cd17a6880" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d21a3-c13d-7247-9e94-5f2916e2208f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019d21a3-c13d-7c3d-8034-3634fd26df44" 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_019d21a3-c13d-7415-a898-7df148013a08" 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_019d21a3-c13d-7c3d-8034-3634fd26df44" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d21a3-c13d-7415-a898-7df148013a08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019d21a3-c13d-7193-ac18-d68eb5d33030" 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_019d21a3-c13d-7c3d-8034-3634fd26df44" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019d21a3-c13d-7193-ac18-d68eb5d33030" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_019d21a3-c13d-7ecc-8eb8-25140e9fd7c8" 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_InterestAndFeeIncomeLoansAndLeases_019d21a3-c13d-720f-a97d-32226b996481" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019d21a3-c13d-7ecc-8eb8-25140e9fd7c8" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_019d21a3-c13d-720f-a97d-32226b996481" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019d21a3-c13d-7911-b914-d860969dfb09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019d21a3-c13d-7ecc-8eb8-25140e9fd7c8" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019d21a3-c13d-7911-b914-d860969dfb09" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DividendsOnOtherInvestments_019d21a3-c13d-7878-b089-8b884958e705" xlink:href="ck1437958-20260331.xsd#ck1437958_DividendsOnOtherInvestments"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019d21a3-c13d-7ecc-8eb8-25140e9fd7c8" xlink:to="loc_ck1437958_DividendsOnOtherInvestments_019d21a3-c13d-7878-b089-8b884958e705" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_019d21a3-c13d-720b-b69d-86f3fe27de5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeDepositsWithFinancialInstitutions"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_019d21a3-c13d-7ecc-8eb8-25140e9fd7c8" xlink:to="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_019d21a3-c13d-720b-b69d-86f3fe27de5e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_019d21a3-c13d-78be-b460-b6287e32c286" 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_ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome_019d21a3-c13d-72c3-8b68-7a20aea37bf6" xlink:href="ck1437958-20260331.xsd#ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019d21a3-c13d-78be-b460-b6287e32c286" xlink:to="loc_ck1437958_NoninterestIncomeExcludingBaaSProgramIncomeAndBaaSIndemnificationIncome_019d21a3-c13d-72c3-8b68-7a20aea37bf6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019d21a3-c13d-7454-bdad-b0bf6e3282ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_019d21a3-c13d-78be-b460-b6287e32c286" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019d21a3-c13d-7454-bdad-b0bf6e3282ae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_019d21a3-c13d-780c-bc11-04da229dbda8" 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_019d21a3-c13d-7a93-9a73-f8e237b6b8b6" 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_019d21a3-c13d-780c-bc11-04da229dbda8" xlink:to="loc_us-gaap_InterestExpenseDeposits_019d21a3-c13d-7a93-9a73-f8e237b6b8b6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseBorrowings_019d21a3-c13d-7f4e-b23f-4aeb58a45c9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseBorrowings"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpenseOperating_019d21a3-c13d-780c-bc11-04da229dbda8" xlink:to="loc_us-gaap_InterestExpenseBorrowings_019d21a3-c13d-7f4e-b23f-4aeb58a45c9a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_019d21a3-c13d-7496-8326-fed30b154ded" 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_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-79dd-85da-46bc40ffa2d8" xlink:href="ck1437958-20260331.xsd#ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019d21a3-c13d-7496-8326-fed30b154ded" xlink:to="loc_ck1437958_NoninterestExpenseExcludingBaaSLoanAndBaaSFraudExpense_019d21a3-c13d-79dd-85da-46bc40ffa2d8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_BankingServiceExpenses_019d21a3-c13d-7f34-baa5-80ad2d6f0ba2" xlink:href="ck1437958-20260331.xsd#ck1437958_BankingServiceExpenses"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_019d21a3-c13d-7496-8326-fed30b154ded" xlink:to="loc_ck1437958_BankingServiceExpenses_019d21a3-c13d-7f34-baa5-80ad2d6f0ba2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_019d21a3-c13d-7bdf-8846-1d42fe3c4d95" 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_019d21a3-c13d-71d8-a5ae-e7bec75e725b" 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_019d21a3-c13d-7bdf-8846-1d42fe3c4d95" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_019d21a3-c13d-71d8-a5ae-e7bec75e725b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_019d21a3-c13d-7572-af6d-b3ace5db74b3" 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_019d21a3-c13d-7bdf-8846-1d42fe3c4d95" xlink:to="loc_us-gaap_InterestExpenseOperating_019d21a3-c13d-7572-af6d-b3ace5db74b3" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEUNAUDITED" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMEUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d21a3-c13d-71fc-a30a-143f139e6468" 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_019d21a3-c13d-75c3-8533-4541c2e9ed0c" 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_019d21a3-c13d-71fc-a30a-143f139e6468" xlink:to="loc_us-gaap_NetIncomeLoss_019d21a3-c13d-75c3-8533-4541c2e9ed0c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d21a3-c13d-7338-a566-f717e4ebdf0f" 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_019d21a3-c13d-71fc-a30a-143f139e6468" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d21a3-c13d-7338-a566-f717e4ebdf0f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d21a3-c13d-70de-9ad4-1e187891a865" 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_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_019d21a3-c13d-7956-9c7a-d1f2449a3fa9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d21a3-c13d-70de-9ad4-1e187891a865" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_019d21a3-c13d-7956-9c7a-d1f2449a3fa9" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d21a3-c13d-7f8e-b4db-317a433cdafa" 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_019d21a3-c13d-7b3f-a0ec-5bfd73d619d9" 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_019d21a3-c13d-7f8e-b4db-317a433cdafa" xlink:to="loc_us-gaap_NetIncomeLoss_019d21a3-c13d-7b3f-a0ec-5bfd73d619d9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-76e1-ab0a-a06b7fc9285a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d21a3-c13d-7f8e-b4db-317a433cdafa" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-76e1-ab0a-a06b7fc9285a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForOtherCreditLosses_019d21a3-c13d-71db-9e71-65648b6f85fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProvisionForOtherCreditLosses"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_ProvisionForOtherCreditLosses_019d21a3-c13d-71db-9e71-65648b6f85fc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019d21a3-c13d-70b8-8b25-430975093da3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019d21a3-c13d-70b8-8b25-430975093da3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets_019d21a3-c13d-7902-b3db-5ca0ea8a0d64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnDispositionOfAssets"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets_019d21a3-c13d-7902-b3db-5ca0ea8a0d64" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_IncreaseDecreaseInOperatingLeaseRightOfUseAssets_019d21a3-c13d-730b-af3a-90a9857d415f" xlink:href="ck1437958-20260331.xsd#ck1437958_IncreaseDecreaseInOperatingLeaseRightOfUseAssets"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_ck1437958_IncreaseDecreaseInOperatingLeaseRightOfUseAssets_019d21a3-c13d-730b-af3a-90a9857d415f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_IncreaseDecreaseInOperatingLeaseLiabilities_019d21a3-c13d-72ed-85d5-c39ab1598c0b" xlink:href="ck1437958-20260331.xsd#ck1437958_IncreaseDecreaseInOperatingLeaseLiabilities"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_ck1437958_IncreaseDecreaseInOperatingLeaseLiabilities_019d21a3-c13d-72ed-85d5-c39ab1598c0b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019d21a3-c13d-78bb-a600-bd48ac241755" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_019d21a3-c13d-78bb-a600-bd48ac241755" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d21a3-c13d-7d68-bb12-49250d0bb276" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d21a3-c13d-7d68-bb12-49250d0bb276" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019d21a3-c13d-7f1b-8ee3-0f5d91c03295" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_ShareBasedCompensation_019d21a3-c13d-7f1b-8ee3-0f5d91c03295" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_019d21a3-c13d-7cff-85a1-b3ba3c5a2cef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_LifeInsuranceCorporateOrBankOwnedChangeInValue_019d21a3-c13d-7cff-85a1-b3ba3c5a2cef" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019d21a3-c13d-793e-9834-6a26f65f6975" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019d21a3-c13d-793e-9834-6a26f65f6975" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInReceivables_019d21a3-c13d-7884-ba2d-11234c26d426" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInReceivables"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_IncreaseDecreaseInReceivables_019d21a3-c13d-7884-ba2d-11234c26d426" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_IncreaseDecreaseInReceivablesCreditEnhancementAsset_019d21a3-c13d-7b80-8840-704a0abb4bd8" xlink:href="ck1437958-20260331.xsd#ck1437958_IncreaseDecreaseInReceivablesCreditEnhancementAsset"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_ck1437958_IncreaseDecreaseInReceivablesCreditEnhancementAsset_019d21a3-c13d-7b80-8840-704a0abb4bd8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_019d21a3-c13d-734d-8cad-84f4c9816f95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_019d21a3-c13d-734d-8cad-84f4c9816f95" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019ddfe9-45c2-7627-8f3c-ef9ad03d3a08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
    <link:calculationArc order="14" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities_019d21a3-c13d-77c6-a41d-7df1d0224618" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019ddfe9-45c2-7627-8f3c-ef9ad03d3a08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" 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_ck1437958_PaymentForProceedsFromOtherInvestments_019d21a3-c13d-791b-9a98-9b8e3edea63a" xlink:href="ck1437958-20260331.xsd#ck1437958_PaymentForProceedsFromOtherInvestments"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_ck1437958_PaymentForProceedsFromOtherInvestments_019d21a3-c13d-791b-9a98-9b8e3edea63a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireEquitySecuritiesFvNi_019d21a3-c13d-7ad4-b3ca-1754cffb4f08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireEquitySecuritiesFvNi"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_us-gaap_PaymentsToAcquireEquitySecuritiesFvNi_019d21a3-c13d-7ad4-b3ca-1754cffb4f08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_PrincipalPaydownsOfInvestmentSecuritiesAvailableForSale_019d21a3-c13d-739f-b2b5-361dfc06799f" xlink:href="ck1437958-20260331.xsd#ck1437958_PrincipalPaydownsOfInvestmentSecuritiesAvailableForSale"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_ck1437958_PrincipalPaydownsOfInvestmentSecuritiesAvailableForSale_019d21a3-c13d-739f-b2b5-361dfc06799f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities_019d21a3-c13d-734e-b491-1de2f2cdf579" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities_019d21a3-c13d-734e-b491-1de2f2cdf579" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireIntangibleAssets_019d21a3-c13d-7b65-b0ae-e5501ddafa53" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireIntangibleAssets"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_us-gaap_PaymentsToAcquireIntangibleAssets_019d21a3-c13d-7b65-b0ae-e5501ddafa53" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfOtherReceivables_019d21a3-c13d-714e-8f9c-042f9358a5f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfOtherReceivables"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_us-gaap_ProceedsFromSaleOfOtherReceivables_019d21a3-c13d-714e-8f9c-042f9358a5f4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromLoansReceivable_019d21a3-c13d-785b-8feb-ee901131a29e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForProceedsFromLoansReceivable"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_us-gaap_PaymentsForProceedsFromLoansReceivable_019d21a3-c13d-785b-8feb-ee901131a29e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherLoansAndLeases_019d21a3-c13d-70cd-99ee-0a5bcab987e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForProceedsFromOtherLoansAndLeases"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherLoansAndLeases_019d21a3-c13d-70cd-99ee-0a5bcab987e9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_IncreaseDecreaseInLoansReceivableNet_019d21a3-c13d-7859-ad90-012f11878b94" xlink:href="ck1437958-20260331.xsd#ck1437958_IncreaseDecreaseInLoansReceivableNet"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_ck1437958_IncreaseDecreaseInLoansReceivableNet_019d21a3-c13d-7859-ad90-012f11878b94" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019de00a-2f6c-72ad-9bb3-01555ba95bee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-79a1-997c-77817b922a89" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019de00a-2f6c-72ad-9bb3-01555ba95bee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-7aa1-ba94-5828310fd1f7" 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_IncreaseDecreaseInDemandDeposits_019d21a3-c13d-76db-84d1-9b0ef5ea4052" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInDemandDeposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-7aa1-ba94-5828310fd1f7" xlink:to="loc_us-gaap_IncreaseDecreaseInDemandDeposits_019d21a3-c13d-76db-84d1-9b0ef5ea4052" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTimeDeposits_019d21a3-c13d-750f-a3d8-b84892dba40a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInTimeDeposits"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-7aa1-ba94-5828310fd1f7" xlink:to="loc_us-gaap_IncreaseDecreaseInTimeDeposits_019d21a3-c13d-750f-a3d8-b84892dba40a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_ProceedsFromStockOptionsExercisedNetOfSharesWithheldToCover_019d21a3-c13d-7b8d-ab5e-bbee8b20b54c" xlink:href="ck1437958-20260331.xsd#ck1437958_ProceedsFromStockOptionsExercisedNetOfSharesWithheldToCover"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-7aa1-ba94-5828310fd1f7" xlink:to="loc_ck1437958_ProceedsFromStockOptionsExercisedNetOfSharesWithheldToCover_019d21a3-c13d-7b8d-ab5e-bbee8b20b54c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_019d21a3-c13d-70c5-bfe9-76628bf68eec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-7aa1-ba94-5828310fd1f7" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_019d21a3-c13d-70c5-bfe9-76628bf68eec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_019d21a3-c13d-7262-bfb0-6fa794c1c81e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceInitialPublicOffering"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-7aa1-ba94-5828310fd1f7" xlink:to="loc_us-gaap_ProceedsFromIssuanceInitialPublicOffering_019d21a3-c13d-7262-bfb0-6fa794c1c81e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019d21a3-c13d-72ce-90c7-d8dfa70a0315" 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_019d21a3-c13d-7888-8eaf-663f82a131fa" 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_019d21a3-c13d-72ce-90c7-d8dfa70a0315" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d21a3-c13d-7888-8eaf-663f82a131fa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-7567-8648-448c6fac968b" 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_019d21a3-c13d-72ce-90c7-d8dfa70a0315" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d21a3-c13d-7567-8648-448c6fac968b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-77a2-ba5d-a7e0d6b404cb" 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_019d21a3-c13d-72ce-90c7-d8dfa70a0315" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d21a3-c13d-77a2-ba5d-a7e0d6b404cb" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/InvestmentsSecuritiesAmortizedCostandFairValuesofInvestmentsinDebtSecuritiesDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#InvestmentsSecuritiesAmortizedCostandFairValuesofInvestmentsinDebtSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/InvestmentsSecuritiesAmortizedCostandFairValuesofInvestmentsinDebtSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-72ba-9df7-7b2565c08430" 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_019d21a3-c13d-7feb-84f8-6fe1c2f81b39" 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_019d21a3-c13d-72ba-9df7-7b2565c08430" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain_019d21a3-c13d-7feb-84f8-6fe1c2f81b39" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_019d21a3-c13d-7b33-96b9-f7068a112705" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-72ba-9df7-7b2565c08430" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss_019d21a3-c13d-7b33-96b9-f7068a112705" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019d21a3-c13d-7ffc-91c5-ec9666d56450" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-72ba-9df7-7b2565c08430" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019d21a3-c13d-7ffc-91c5-ec9666d56450" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest_019d21a3-c13d-77f9-a4a1-fa8ad8e999c0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-72ba-9df7-7b2565c08430" xlink:to="loc_us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest_019d21a3-c13d-77f9-a4a1-fa8ad8e999c0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-7744-9ddc-2094eba366f8" 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_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019d21a3-c13d-79af-9dd6-b1a8c14cf975" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-7744-9ddc-2094eba366f8" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019d21a3-c13d-79af-9dd6-b1a8c14cf975" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019d21a3-c13d-7a9b-ae30-5c748daf4099" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-7744-9ddc-2094eba366f8" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019d21a3-c13d-7a9b-ae30-5c748daf4099" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d21a3-c13d-7e43-b07b-7b3748f96f00" 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_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-7744-9ddc-2094eba366f8" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d21a3-c13d-7e43-b07b-7b3748f96f00" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest_019d21a3-c13d-747a-81ae-daca9d6da9e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-7744-9ddc-2094eba366f8" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest_019d21a3-c13d-747a-81ae-daca9d6da9e2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostBeforeAllowanceForCreditLoss_019d21a3-c13d-77f5-b762-4fd5e6a32645" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostBeforeAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityAccumulatedUnrecognizedGain_019d21a3-c13d-7f30-9d17-d85e097a01f9" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityAccumulatedUnrecognizedGain"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostBeforeAllowanceForCreditLoss_019d21a3-c13d-77f5-b762-4fd5e6a32645" xlink:to="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityAccumulatedUnrecognizedGain_019d21a3-c13d-7f30-9d17-d85e097a01f9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityAccumulatedGrossUnrealizedLossBeforeTax_019d21a3-c13d-7a23-8db6-ffdc7930b081" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostBeforeAllowanceForCreditLoss_019d21a3-c13d-77f5-b762-4fd5e6a32645" xlink:to="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityAccumulatedGrossUnrealizedLossBeforeTax_019d21a3-c13d-7a23-8db6-ffdc7930b081" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue_019d21a3-c13d-7aa5-b4ee-707d77dda0f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostBeforeAllowanceForCreditLoss_019d21a3-c13d-77f5-b762-4fd5e6a32645" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityFairValue_019d21a3-c13d-7aa5-b4ee-707d77dda0f3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAllowanceForCreditLoss_019d21a3-c13d-7c3e-b51d-dca8db6be2de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAllowanceForCreditLoss"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAmortizedCostBeforeAllowanceForCreditLoss_019d21a3-c13d-77f5-b762-4fd5e6a32645" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAndHeldToMaturityAllowanceForCreditLoss_019d21a3-c13d-7c3e-b51d-dca8db6be2de" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/InvestmentsSecuritiesAmortizedCostandFairValueofDebtSecuritiesbyContractualMaturityDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#InvestmentsSecuritiesAmortizedCostandFairValueofDebtSecuritiesbyContractualMaturityDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/InvestmentsSecuritiesAmortizedCostandFairValueofDebtSecuritiesbyContractualMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-73e7-a153-006f3f3c203e" 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_DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityWithoutSingleMaturityDate_019d21a3-c13d-728c-85f6-23ae445576e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityWithoutSingleMaturityDate"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-73e7-a153-006f3f3c203e" xlink:to="loc_us-gaap_DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityWithoutSingleMaturityDate_019d21a3-c13d-728c-85f6-23ae445576e3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019d21a3-c13d-7fcd-8dbf-d03f601a5adb" 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_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_019d21a3-c13d-728a-860a-574084d84404" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesFairValue_019d21a3-c13d-7fcd-8dbf-d03f601a5adb" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_019d21a3-c13d-728a-860a-574084d84404" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-7b55-a49d-d4fb2c65fbda" 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_019d21a3-c13d-756b-9dcf-a69ced1bcdae" 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_019d21a3-c13d-7b55-a49d-d4fb2c65fbda" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost_019d21a3-c13d-756b-9dcf-a69ced1bcdae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d21a3-c13d-7264-b21b-d3fe4d3f2c08" 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_019d21a3-c13d-75fa-b9bd-4802f9d22da8" 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_019d21a3-c13d-7264-b21b-d3fe4d3f2c08" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue_019d21a3-c13d-75fa-b9bd-4802f9d22da8" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/InvestmentsSecuritiesSummaryofInvestmentSecuritiesContinuousUnrealizedLossPositionDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#InvestmentsSecuritiesSummaryofInvestmentSecuritiesContinuousUnrealizedLossPositionDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/InvestmentsSecuritiesSummaryofInvestmentSecuritiesContinuousUnrealizedLossPositionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019d21a3-c13d-75aa-907d-e0d2bc982f69" 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_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019d21a3-c13d-7bbd-8ae4-97cf549818c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019d21a3-c13d-75aa-907d-e0d2bc982f69" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019d21a3-c13d-7bbd-8ae4-97cf549818c8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019d21a3-c13d-7970-a4e2-ec5eab4c770e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019d21a3-c13d-75aa-907d-e0d2bc982f69" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019d21a3-c13d-7970-a4e2-ec5eab4c770e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-7083-861c-d806276f2a37" 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_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_019d21a3-c13d-7827-acff-5eed8be9155e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-7083-861c-d806276f2a37" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_019d21a3-c13d-7827-acff-5eed8be9155e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d21a3-c13d-770f-b48e-d57d97f25b2b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-7083-861c-d806276f2a37" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d21a3-c13d-770f-b48e-d57d97f25b2b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-7d82-8324-eb18cbab37d9" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019d21a3-c13d-7ac9-b0da-0a50255724c3" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-7d82-8324-eb18cbab37d9" xlink:to="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019d21a3-c13d-7ac9-b0da-0a50255724c3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d21a3-c13d-7ce3-b94f-275313097a75" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-7d82-8324-eb18cbab37d9" xlink:to="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d21a3-c13d-7ce3-b94f-275313097a75" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-77c8-8427-7c13a4010370" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019d21a3-c13d-755f-9a34-bc07d912a6c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-77c8-8427-7c13a4010370" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019d21a3-c13d-755f-9a34-bc07d912a6c3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d21a3-c13d-7bd8-bdf5-e5dd03507878" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_019d21a3-c13d-77c8-8427-7c13a4010370" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d21a3-c13d-7bd8-bdf5-e5dd03507878" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue_019d21a3-c13d-79bc-bcb8-3f7b2aae0984" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_019d21a3-c13d-7ca0-a220-6af74c843865" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue_019d21a3-c13d-79bc-bcb8-3f7b2aae0984" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue_019d21a3-c13d-7ca0-a220-6af74c843865" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_019d21a3-c13d-7b4e-bcb4-0ac20c1867dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue_019d21a3-c13d-79bc-bcb8-3f7b2aae0984" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue_019d21a3-c13d-7b4e-bcb4-0ac20c1867dd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue_019d21a3-c13d-7e25-a379-36dbad5a58d3" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLonger_019d21a3-c13d-7b92-876a-cf7d2871e6a0" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue_019d21a3-c13d-7e25-a379-36dbad5a58d3" xlink:to="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPosition12MonthsOrLonger_019d21a3-c13d-7b92-876a-cf7d2871e6a0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12Months_019d21a3-c13d-7396-aa66-dacdda254999" xlink:href="ck1437958-20260331.xsd#ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityUnrealizedLossPositionFairValue_019d21a3-c13d-7e25-a379-36dbad5a58d3" xlink:to="loc_ck1437958_DebtSecuritiesAvailableForSaleAndHeldToMaturityContinuousUnrealizedLossPositionLessThan12Months_019d21a3-c13d-7396-aa66-dacdda254999" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/LoansandAllowanceforCreditLossesCompositionofLoanPortfolioDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#LoansandAllowanceforCreditLossesCompositionofLoanPortfolioDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/LoansandAllowanceforCreditLossesCompositionofLoanPortfolioDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-731f-acc4-eeecf12f68bc" 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_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount_019d21a3-c13d-73ca-aa99-b00e7746eac8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-731f-acc4-eeecf12f68bc" xlink:to="loc_us-gaap_FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount_019d21a3-c13d-73ca-aa99-b00e7746eac8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess_019d21a3-c13d-711d-a637-284279e99d7f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-731f-acc4-eeecf12f68bc" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLossFeeAndLoanInProcess_019d21a3-c13d-711d-a637-284279e99d7f" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/LoansandAllowanceforCreditLossesSummaryofRiskCategoryofLoansbyClassofLoansDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#LoansandAllowanceforCreditLossesSummaryofRiskCategoryofLoansbyClassofLoansDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/LoansandAllowanceforCreditLossesSummaryofRiskCategoryofLoansbyClassofLoansDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" 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_FinancingReceivableExcludingAccruedInterestRevolving_019d21a3-c13d-7619-ada5-e6f0da8ab646" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolving"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolving_019d21a3-c13d-7619-ada5-e6f0da8ab646" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan_019d21a3-c13d-7d60-b7da-be9b639ebad6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan_019d21a3-c13d-7d60-b7da-be9b639ebad6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_019d21a3-c13d-762d-beff-c67b100a4d1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_019d21a3-c13d-762d-beff-c67b100a4d1d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_019d21a3-c13d-731b-8b85-712bcdfd20ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_019d21a3-c13d-731b-8b85-712bcdfd20ec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_019d21a3-c13d-7a7f-9691-dcdfd99101f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_019d21a3-c13d-7a7f-9691-dcdfd99101f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_019d21a3-c13d-746a-b046-c631b1f4dc61" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_019d21a3-c13d-746a-b046-c631b1f4dc61" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_019d21a3-c13d-727f-9c3d-4babe80ca4e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_019d21a3-c13d-727f-9c3d-4babe80ca4e8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_019d21a3-c13d-731a-8b57-b34e54d44bfd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_019d21a3-c13d-712f-929d-ead3e0841b7f" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_019d21a3-c13d-731a-8b57-b34e54d44bfd" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/DepositsCompositionofConsolidatedDepositsDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#DepositsCompositionofConsolidatedDepositsDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/DepositsCompositionofConsolidatedDepositsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_019d21a3-c13d-7eaa-ad7a-48cf849e005f" 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_ck1437958_CoreDeposits_019d21a3-c13d-7504-ad79-8d07b8717ea1" xlink:href="ck1437958-20260331.xsd#ck1437958_CoreDeposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d21a3-c13d-7eaa-ad7a-48cf849e005f" xlink:to="loc_ck1437958_CoreDeposits_019d21a3-c13d-7504-ad79-8d07b8717ea1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDomesticDepositBrokered_019d21a3-c13d-7470-bdea-3142c901d082" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestBearingDomesticDepositBrokered"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d21a3-c13d-7eaa-ad7a-48cf849e005f" xlink:to="loc_us-gaap_NoninterestBearingDomesticDepositBrokered_019d21a3-c13d-7470-bdea-3142c901d082" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_TimeDepositsLessThan250000_019d21a3-c13d-71da-9e3b-2f1e9f374e91" xlink:href="ck1437958-20260331.xsd#ck1437958_TimeDepositsLessThan250000"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d21a3-c13d-7eaa-ad7a-48cf849e005f" xlink:to="loc_ck1437958_TimeDepositsLessThan250000_019d21a3-c13d-71da-9e3b-2f1e9f374e91" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_TimeDeposits250000OrMore_019d21a3-c13d-7259-86d0-1654e0d9bf7a" xlink:href="ck1437958-20260331.xsd#ck1437958_TimeDeposits250000OrMore"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_019d21a3-c13d-7eaa-ad7a-48cf849e005f" xlink:to="loc_ck1437958_TimeDeposits250000OrMore_019d21a3-c13d-7259-86d0-1654e0d9bf7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_CoreDeposits_019d21a3-c13d-72b6-91d7-b51c0416b0ec" xlink:href="ck1437958-20260331.xsd#ck1437958_CoreDeposits"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsMoneyMarketDepositsAndNegotiableOrderOfWithdrawalNOW_019d21a3-c13d-7999-8cf1-83cce4d6c55c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositsMoneyMarketDepositsAndNegotiableOrderOfWithdrawalNOW"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_CoreDeposits_019d21a3-c13d-72b6-91d7-b51c0416b0ec" xlink:to="loc_us-gaap_DepositsMoneyMarketDepositsAndNegotiableOrderOfWithdrawalNOW_019d21a3-c13d-7999-8cf1-83cce4d6c55c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDomesticDepositDemand_019d21a3-c13d-763f-85d6-02559ac0d57b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoninterestBearingDomesticDepositDemand"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_CoreDeposits_019d21a3-c13d-72b6-91d7-b51c0416b0ec" xlink:to="loc_us-gaap_NoninterestBearingDomesticDepositDemand_019d21a3-c13d-763f-85d6-02559ac0d57b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsSavingsDeposits_019d21a3-c13d-70ce-bd53-d2ef93df1921" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositsSavingsDeposits"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_ck1437958_CoreDeposits_019d21a3-c13d-72b6-91d7-b51c0416b0ec" xlink:to="loc_us-gaap_DepositsSavingsDeposits_019d21a3-c13d-70ce-bd53-d2ef93df1921" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/DepositsScheduleofMaturityDistributionofTimeDepositsDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#DepositsScheduleofMaturityDistributionofTimeDepositsDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/DepositsScheduleofMaturityDistributionofTimeDepositsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDeposits_019d21a3-c13d-75d9-87fa-51acf63b638f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimeDeposits"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDepositMaturitiesYearOne_019d21a3-c13d-7a81-a013-bc4326c706bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimeDepositMaturitiesYearOne"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_TimeDeposits_019d21a3-c13d-75d9-87fa-51acf63b638f" xlink:to="loc_us-gaap_TimeDepositMaturitiesYearOne_019d21a3-c13d-7a81-a013-bc4326c706bf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDepositMaturitiesYearTwo_019d21a3-c13d-7150-a9f2-c6f58295c44c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimeDepositMaturitiesYearTwo"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_TimeDeposits_019d21a3-c13d-75d9-87fa-51acf63b638f" xlink:to="loc_us-gaap_TimeDepositMaturitiesYearTwo_019d21a3-c13d-7150-a9f2-c6f58295c44c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDepositMaturitiesYearThree_019d21a3-c13d-7d8c-aa63-d4420ff155f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimeDepositMaturitiesYearThree"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_TimeDeposits_019d21a3-c13d-75d9-87fa-51acf63b638f" xlink:to="loc_us-gaap_TimeDepositMaturitiesYearThree_019d21a3-c13d-7d8c-aa63-d4420ff155f9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDepositMaturitiesYearFour_019d21a3-c13d-7df2-944c-65cb24dd7929" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimeDepositMaturitiesYearFour"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_TimeDeposits_019d21a3-c13d-75d9-87fa-51acf63b638f" xlink:to="loc_us-gaap_TimeDepositMaturitiesYearFour_019d21a3-c13d-7df2-944c-65cb24dd7929" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDepositMaturitiesYearFive_019d21a3-c13d-7da7-b046-9f2d3977bf3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TimeDepositMaturitiesYearFive"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_TimeDeposits_019d21a3-c13d-75d9-87fa-51acf63b638f" xlink:to="loc_us-gaap_TimeDepositMaturitiesYearFive_019d21a3-c13d-7da7-b046-9f2d3977bf3b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/LeasesSummaryofMinimumAnnualLeasePaymentsunderLeaseTermsDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#LeasesSummaryofMinimumAnnualLeasePaymentsunderLeaseTermsDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/LeasesSummaryofMinimumAnnualLeasePaymentsunderLeaseTermsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c1fa-71e1-ba24-bed042e765fe" 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_019d21a3-c1fa-7962-8189-cb5d390ec159" 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_019d21a3-c1fa-71e1-ba24-bed042e765fe" xlink:to="loc_us-gaap_FinanceLeaseLiability_019d21a3-c1fa-7962-8189-cb5d390ec159" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_019d21a3-c1fa-7b4b-8dbb-c95929dbe64e" 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_019d21a3-c1fa-71e1-ba24-bed042e765fe" xlink:to="loc_us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_019d21a3-c1fa-7b4b-8dbb-c95929dbe64e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c1fa-7fab-9dcc-9c07e9feb280" 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_ck1437958_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour_019d21a3-c1fa-7684-85db-8cfb8321d8ba" xlink:href="ck1437958-20260331.xsd#ck1437958_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c1fa-7fab-9dcc-9c07e9feb280" xlink:to="loc_ck1437958_LesseeOperatingLeaseLiabilityToBePaidAfterYearFour_019d21a3-c1fa-7684-85db-8cfb8321d8ba" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_019d21a3-c1fa-7c48-9813-1fd0cc22a25d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c1fa-7fab-9dcc-9c07e9feb280" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_019d21a3-c1fa-7c48-9813-1fd0cc22a25d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_019d21a3-c1fa-750a-accf-2de80eaf69b0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c1fa-7fab-9dcc-9c07e9feb280" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsRemainderOfFiscalYear_019d21a3-c1fa-750a-accf-2de80eaf69b0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_019d21a3-c1fa-70ca-973c-e96fe8c29b77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c1fa-7fab-9dcc-9c07e9feb280" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_019d21a3-c1fa-70ca-973c-e96fe8c29b77" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_019d21a3-c1fa-7365-a214-61cb410bbfee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c1fa-7fab-9dcc-9c07e9feb280" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_019d21a3-c1fa-7365-a214-61cb410bbfee" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_019d21a3-c1fa-7510-94bc-8f53a1b2d7c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c1fa-7fab-9dcc-9c07e9feb280" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_019d21a3-c1fa-7510-94bc-8f53a1b2d7c5" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/LeasesSummaryofMinimumAnnualLeasePaymentsunderLeaseTermsDetails_1" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#LeasesSummaryofMinimumAnnualLeasePaymentsunderLeaseTermsDetails_1"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/LeasesSummaryofMinimumAnnualLeasePaymentsunderLeaseTermsDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c13e-74c0-a8f3-3d3581887fc5" 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_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_019d21a3-c13e-7dae-9d5c-11822e8dfb73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c13e-74c0-a8f3-3d3581887fc5" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_019d21a3-c13e-7dae-9d5c-11822e8dfb73" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_019d21a3-c13e-7c0d-a902-5a646cb6ad1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c13e-74c0-a8f3-3d3581887fc5" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_019d21a3-c13e-7c0d-a902-5a646cb6ad1f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear_019d21a3-c1fa-7e9a-a2e0-81f6dd6a7cbe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c13e-74c0-a8f3-3d3581887fc5" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear_019d21a3-c1fa-7e9a-a2e0-81f6dd6a7cbe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_ck1437958_FinanceLeaseLiabilityToBePaidYearFiveAndThereafter_019d21a3-c1fa-7d93-b0e9-eec16faaf836" xlink:href="ck1437958-20260331.xsd#ck1437958_FinanceLeaseLiabilityToBePaidYearFiveAndThereafter"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c13e-74c0-a8f3-3d3581887fc5" xlink:to="loc_ck1437958_FinanceLeaseLiabilityToBePaidYearFiveAndThereafter_019d21a3-c1fa-7d93-b0e9-eec16faaf836" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_019d21a3-c1fa-77be-b98e-1915400696c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c13e-74c0-a8f3-3d3581887fc5" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_019d21a3-c1fa-77be-b98e-1915400696c3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_019d21a3-c1fa-7ce9-89d0-3c07f667e29b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_FinanceLeaseLiabilityPaymentsDue_019d21a3-c13e-74c0-a8f3-3d3581887fc5" xlink:to="loc_us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_019d21a3-c1fa-7ce9-89d0-3c07f667e29b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_019d21a3-c13e-7c30-be8c-dcb38e99548e" 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_019d21a3-c13e-7fcb-8027-464989cab16b" 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_019d21a3-c13e-7c30-be8c-dcb38e99548e" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_019d21a3-c13e-7fcb-8027-464989cab16b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_019d21a3-c13e-7851-a870-e0bd43e5855d" 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_019d21a3-c13e-7c30-be8c-dcb38e99548e" xlink:to="loc_us-gaap_OperatingLeaseLiability_019d21a3-c13e-7851-a870-e0bd43e5855d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/LeasesSummaryofComponentsofTotalLeaseExpenseandOperatingCashFlowsDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#LeasesSummaryofComponentsofTotalLeaseExpenseandOperatingCashFlowsDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/LeasesSummaryofComponentsofTotalLeaseExpenseandOperatingCashFlowsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseCost_019d21a3-c1fa-7bfb-be6b-fe0033ca1524" 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_VariableLeaseCost_019d21a3-c1fa-74cc-a102-01a73655fda8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableLeaseCost"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019d21a3-c1fa-7bfb-be6b-fe0033ca1524" xlink:to="loc_us-gaap_VariableLeaseCost_019d21a3-c1fa-74cc-a102-01a73655fda8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost_019d21a3-c1fa-7e0b-b593-4d5b4beecb91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseCost"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019d21a3-c1fa-7bfb-be6b-fe0033ca1524" xlink:to="loc_us-gaap_OperatingLeaseCost_019d21a3-c1fa-7e0b-b593-4d5b4beecb91" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization_019d21a3-c1fa-7297-a1d1-d12bb2cbcbd8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019d21a3-c1fa-7bfb-be6b-fe0033ca1524" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAssetAmortization_019d21a3-c1fa-7297-a1d1-d12bb2cbcbd8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseInterestExpense_019d21a3-c1fa-78e8-b52a-8377cdbf137a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseInterestExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LeaseCost_019d21a3-c1fa-7bfb-be6b-fe0033ca1524" xlink:to="loc_us-gaap_FinanceLeaseInterestExpense_019d21a3-c1fa-78e8-b52a-8377cdbf137a" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.coastalbank.com/role/EarningsPerCommonShareScheduleofComputationofBasicandDilutedEarningsPerCommonShareDetails" xlink:type="simple" xlink:href="ck1437958-20260331.xsd#EarningsPerCommonShareScheduleofComputationofBasicandDilutedEarningsPerCommonShareDetails"/>
  <link:calculationLink xlink:role="http://www.coastalbank.com/role/EarningsPerCommonShareScheduleofComputationofBasicandDilutedEarningsPerCommonShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d21a3-c1fa-797a-b763-33dae7a89526" 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_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019d21a3-c1fa-7833-be0d-c386136141a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d21a3-c1fa-797a-b763-33dae7a89526" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019d21a3-c1fa-7833-be0d-c386136141a1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d21a3-c1fa-7611-ba72-4506ff4117c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d21a3-c1fa-797a-b763-33dae7a89526" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d21a3-c1fa-7611-ba72-4506ff4117c2" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
