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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019fece9-98cf-7828-91a0-13f4bda0d2d4,g:2bc4f796-c4db-4d39-87a2-537974363bc5-->
<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.firstenergycorp.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="fet-20260930.xsd#CONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:calculationLink xlink:role="http://www.firstenergycorp.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019fece9-9a07-70ef-82cc-89b310f9e556" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostAndExpenseOperating_019fece9-9a07-7992-bea0-30e1807cef16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCostAndExpenseOperating"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019fece9-9a07-70ef-82cc-89b310f9e556" xlink:to="loc_us-gaap_OtherCostAndExpenseOperating_019fece9-9a07-7992-bea0-30e1807cef16" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_019fece9-9a07-7f8b-9e66-f9b6c2383d64" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Depreciation"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019fece9-9a07-70ef-82cc-89b310f9e556" xlink:to="loc_us-gaap_Depreciation_019fece9-9a07-7f8b-9e66-f9b6c2383d64" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_AmortizationDeferralOfRegulatoryAssetNet_019fece9-9a07-7aa6-994e-8f83488a421a" xlink:href="fet-20260930.xsd#fet_AmortizationDeferralOfRegulatoryAssetNet"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019fece9-9a07-70ef-82cc-89b310f9e556" xlink:to="loc_fet_AmortizationDeferralOfRegulatoryAssetNet_019fece9-9a07-7aa6-994e-8f83488a421a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UtilitiesOperatingExpenseTaxes_019fece9-9a07-72a0-af4f-a66819a88019" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UtilitiesOperatingExpenseTaxes"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019fece9-9a07-70ef-82cc-89b310f9e556" xlink:to="loc_us-gaap_UtilitiesOperatingExpenseTaxes_019fece9-9a07-72a0-af4f-a66819a88019" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019fece9-9a07-7729-a6eb-6047c3db7660" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019fece9-9a07-7050-8258-54a11cdbf3b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019fece9-9a07-7729-a6eb-6047c3db7660" xlink:to="loc_us-gaap_Revenues_019fece9-9a07-7050-8258-54a11cdbf3b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019fece9-9a07-74d7-a7c0-ff57575b899a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpenses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019fece9-9a07-7729-a6eb-6047c3db7660" xlink:to="loc_us-gaap_CostsAndExpenses_019fece9-9a07-74d7-a7c0-ff57575b899a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fece9-9a07-74c0-b6e9-a7be1249b36a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019fece9-9a07-79dd-a69a-552cd0ed4804" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fece9-9a07-74c0-b6e9-a7be1249b36a" xlink:to="loc_us-gaap_OperatingIncomeLoss_019fece9-9a07-79dd-a69a-552cd0ed4804" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019fece9-9a07-7a3e-bc33-feb4ab4a2ed1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fece9-9a07-74c0-b6e9-a7be1249b36a" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019fece9-9a07-7a3e-bc33-feb4ab4a2ed1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019fece9-9a07-71f1-a2c8-9447b8dc8c44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fece9-9a07-7be2-9235-6cc24f65bce1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.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_ProfitLoss_019fece9-9a07-71f1-a2c8-9447b8dc8c44" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fece9-9a07-7be2-9235-6cc24f65bce1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-71f7-98fd-a339a59e3fa9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.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_ProfitLoss_019fece9-9a07-71f1-a2c8-9447b8dc8c44" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-71f7-98fd-a339a59e3fa9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fece9-9a07-7b2f-858d-1d41a8127311" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019fece9-9a07-7baa-9a08-991b9e6ef8bf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fece9-9a07-7b2f-858d-1d41a8127311" xlink:to="loc_us-gaap_ProfitLoss_019fece9-9a07-7baa-9a08-991b9e6ef8bf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019fece9-9a07-77ab-84ff-fb9ebbbcab74" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019fece9-9a07-7b2f-858d-1d41a8127311" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019fece9-9a07-77ab-84ff-fb9ebbbcab74" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019fece9-9a07-794c-97ab-e0e0a6c97d7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fece9-9a07-738f-8359-74210aa7d9a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019fece9-9a07-794c-97ab-e0e0a6c97d7f" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fece9-9a07-738f-8359-74210aa7d9a9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestCostsCapitalizedAdjustment_019fece9-9a07-7324-a1d7-d67a70ebfd97" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestCostsCapitalizedAdjustment"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019fece9-9a07-794c-97ab-e0e0a6c97d7f" xlink:to="loc_us-gaap_InterestCostsCapitalizedAdjustment_019fece9-9a07-7324-a1d7-d67a70ebfd97" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeNonoperating_019fece9-9a07-7f51-9754-b8f51813d1e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeNonoperating"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019fece9-9a07-794c-97ab-e0e0a6c97d7f" xlink:to="loc_us-gaap_InvestmentIncomeNonoperating_019fece9-9a07-7f51-9754-b8f51813d1e1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019fece9-9a07-770e-abbc-99e065cd96b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019fece9-9a07-794c-97ab-e0e0a6c97d7f" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019fece9-9a07-770e-abbc-99e065cd96b4" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.firstenergycorp.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="fet-20260930.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:calculationLink xlink:role="http://www.firstenergycorp.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019fece9-9a07-7659-8e6f-e6bd4c244112" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest_019fece9-9a07-7a04-88ab-1d8ce5bc35cf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MembersEquityAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019fece9-9a07-7659-8e6f-e6bd4c244112" xlink:to="loc_us-gaap_MembersEquityAttributableToNoncontrollingInterest_019fece9-9a07-7a04-88ab-1d8ce5bc35cf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquity_019fece9-9a07-730e-afc3-150dda60d029" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MembersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019fece9-9a07-7659-8e6f-e6bd4c244112" xlink:to="loc_us-gaap_MembersEquity_019fece9-9a07-730e-afc3-150dda60d029" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_019fece9-9a07-7cf2-9a8a-c4d51a73b6b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress_019fece9-9a07-7206-8ef0-9931e1136815" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_019fece9-9a07-7cf2-9a8a-c4d51a73b6b5" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentConstructionWorkInProgress_019fece9-9a07-7206-8ef0-9931e1136815" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_NetPlantExcludingConstructionWorkInProgress_019fece9-9a07-7339-85f3-bfe95f5eb646" xlink:href="fet-20260930.xsd#fet_NetPlantExcludingConstructionWorkInProgress"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_019fece9-9a07-7cf2-9a8a-c4d51a73b6b5" xlink:to="loc_fet_NetPlantExcludingConstructionWorkInProgress_019fece9-9a07-7339-85f3-bfe95f5eb646" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019fece9-9a07-7bd1-a28c-370ecd6389bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss_019fece9-9a07-7b2f-a509-ac241b67069a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fece9-9a07-7bd1-a28c-370ecd6389bb" xlink:to="loc_us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss_019fece9-9a07-7b2f-a509-ac241b67069a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_019fece9-9a07-72b9-88e1-470e6f795822" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fece9-9a07-7bd1-a28c-370ecd6389bb" xlink:to="loc_us-gaap_OtherAssetsCurrent_019fece9-9a07-72b9-88e1-470e6f795822" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019fece9-9a07-7d20-bfe7-b4459918a8f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fece9-9a07-7bd1-a28c-370ecd6389bb" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019fece9-9a07-7d20-bfe7-b4459918a8f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019fece9-9a07-7efc-817f-f1035e75be4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019fece9-9a07-7bd1-a28c-370ecd6389bb" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019fece9-9a07-7efc-817f-f1035e75be4d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fece9-9a07-7dce-8326-d5b72a58b537" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019fece9-9a07-737c-ad3a-b61bef12e40a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fece9-9a07-7dce-8326-d5b72a58b537" xlink:to="loc_us-gaap_LimitedLiabilityCompanyLlcMembersEquityIncludingPortionAttributableToNoncontrollingInterest_019fece9-9a07-737c-ad3a-b61bef12e40a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019fece9-9a07-753f-8c6a-3c7bdce92d9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fece9-9a07-7dce-8326-d5b72a58b537" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019fece9-9a07-753f-8c6a-3c7bdce92d9a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019fece9-9a07-7c00-8bf2-1453980a8906" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019fece9-9a07-7dce-8326-d5b72a58b537" xlink:to="loc_us-gaap_Liabilities_019fece9-9a07-7c00-8bf2-1453980a8906" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7218-97f0-a439e8806434" xlink:href="fet-20260930.xsd#fet_DeferredChargesAndOtherAssetsNoncurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019fece9-9a07-7000-9796-f96a0f96dad7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7218-97f0-a439e8806434" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019fece9-9a07-7000-9796-f96a0f96dad7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_019fece9-9a07-7188-b154-cc593d75494a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7218-97f0-a439e8806434" xlink:to="loc_us-gaap_LongTermInvestments_019fece9-9a07-7188-b154-cc593d75494a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019fece9-9a07-7a0e-b078-25705bd6779b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7218-97f0-a439e8806434" xlink:to="loc_us-gaap_Goodwill_019fece9-9a07-7a0e-b078-25705bd6779b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019fece9-9a07-7141-9b00-438f07f62ad0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7218-97f0-a439e8806434" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019fece9-9a07-7141-9b00-438f07f62ad0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_PropertyTaxesReceivableNoncurrent_019fece9-9a07-7d0f-b70c-2f22711eb154" xlink:href="fet-20260930.xsd#fet_PropertyTaxesReceivableNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7218-97f0-a439e8806434" xlink:to="loc_fet_PropertyTaxesReceivableNoncurrent_019fece9-9a07-7d0f-b70c-2f22711eb154" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019fece9-9a07-7de7-aeea-5ebce4740de6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_019fece9-9a07-79ef-8cbd-0547f3cf6d8c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fece9-9a07-7de7-aeea-5ebce4740de6" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentNet_019fece9-9a07-79ef-8cbd-0547f3cf6d8c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7b9a-9397-28d1a80a200f" xlink:href="fet-20260930.xsd#fet_DeferredChargesAndOtherAssetsNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fece9-9a07-7de7-aeea-5ebce4740de6" xlink:to="loc_fet_DeferredChargesAndOtherAssetsNoncurrent_019fece9-9a07-7b9a-9397-28d1a80a200f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019fece9-9a07-76eb-8ea4-71cbcadf5e5b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019fece9-9a07-7de7-aeea-5ebce4740de6" xlink:to="loc_us-gaap_AssetsCurrent_019fece9-9a07-76eb-8ea4-71cbcadf5e5b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7c9f-a322-c5acadddb5c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019fece9-9a07-79da-b176-3c5548f1af52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7c9f-a322-c5acadddb5c8" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent_019fece9-9a07-79da-b176-3c5548f1af52" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_019fece9-9a07-7c98-a0f0-0946db0b8578" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermBorrowings"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7c9f-a322-c5acadddb5c8" xlink:to="loc_us-gaap_ShortTermBorrowings_019fece9-9a07-7c98-a0f0-0946db0b8578" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_019fece9-9a07-7c25-801d-babb074909ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7c9f-a322-c5acadddb5c8" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_019fece9-9a07-7c25-801d-babb074909ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedIncomeTaxesCurrent_019fece9-9a07-7c42-b259-618e12e93d13" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedIncomeTaxesCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7c9f-a322-c5acadddb5c8" xlink:to="loc_us-gaap_AccruedIncomeTaxesCurrent_019fece9-9a07-7c42-b259-618e12e93d13" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPayableCurrent_019fece9-9a07-7546-b568-cdf32f188196" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestPayableCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7c9f-a322-c5acadddb5c8" xlink:to="loc_us-gaap_InterestPayableCurrent_019fece9-9a07-7546-b568-cdf32f188196" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrentAndNoncurrent_019fece9-9a07-7e43-a568-dafd05f68763" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrentAndNoncurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7c9f-a322-c5acadddb5c8" xlink:to="loc_us-gaap_AccountsPayableCurrentAndNoncurrent_019fece9-9a07-7e43-a568-dafd05f68763" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_NetPlantExcludingConstructionWorkInProgress_019fece9-9a07-7098-a8b5-2ffab259456c" xlink:href="fet-20260930.xsd#fet_NetPlantExcludingConstructionWorkInProgress"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciationExcludingConstructionWorkInProgress_019fece9-9a07-753d-aeca-1bc1254b7a4d" xlink:href="fet-20260930.xsd#fet_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciationExcludingConstructionWorkInProgress"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fet_NetPlantExcludingConstructionWorkInProgress_019fece9-9a07-7098-a8b5-2ffab259456c" xlink:to="loc_fet_PublicUtilitiesPropertyPlantAndEquipmentAccumulatedDepreciationExcludingConstructionWorkInProgress_019fece9-9a07-753d-aeca-1bc1254b7a4d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_019fece9-9a07-7a8d-8652-d966542e0dde" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_fet_NetPlantExcludingConstructionWorkInProgress_019fece9-9a07-7098-a8b5-2ffab259456c" xlink:to="loc_us-gaap_PublicUtilitiesPropertyPlantAndEquipmentPlantInService_019fece9-9a07-7a8d-8652-d966542e0dde" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersEquity_019fece9-9a07-78f7-b9a2-2d1fe08e0909" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MembersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019fece9-9a07-7926-98c9-60b03348f227" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_MembersEquity_019fece9-9a07-78f7-b9a2-2d1fe08e0909" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019fece9-9a07-7926-98c9-60b03348f227" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MembersCapital_019fece9-9a07-799e-bfe8-7204e0cd840a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MembersCapital"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_MembersEquity_019fece9-9a07-78f7-b9a2-2d1fe08e0909" xlink:to="loc_us-gaap_MembersCapital_019fece9-9a07-799e-bfe8-7204e0cd840a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019fece9-9a07-747a-991b-8f22f33f5614" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-72d0-a4e8-507102f36029" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019fece9-9a07-747a-991b-8f22f33f5614" xlink:to="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-72d0-a4e8-507102f36029" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7155-9a7b-4e9001678346" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019fece9-9a07-747a-991b-8f22f33f5614" xlink:to="loc_us-gaap_LiabilitiesCurrent_019fece9-9a07-7155-9a7b-4e9001678346" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-7813-a27e-267a8c675ee6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesNoncurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019fece9-9a07-71e3-aedd-6a5d1f8070b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-7813-a27e-267a8c675ee6" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_019fece9-9a07-71e3-aedd-6a5d1f8070b9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019fece9-9a07-7193-8893-0d3ac27a9bc6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-7813-a27e-267a8c675ee6" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019fece9-9a07-7193-8893-0d3ac27a9bc6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RegulatoryLiabilityNoncurrent_019fece9-9a07-7777-a617-83eb94caea84" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RegulatoryLiabilityNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-7813-a27e-267a8c675ee6" xlink:to="loc_us-gaap_RegulatoryLiabilityNoncurrent_019fece9-9a07-7777-a617-83eb94caea84" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019fece9-9a07-7988-a24c-9edd3837700e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-7813-a27e-267a8c675ee6" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019fece9-9a07-7988-a24c-9edd3837700e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_PropertyTaxesPayableNoncurrent_019fece9-9a07-7def-bb14-0ab63d3b896d" xlink:href="fet-20260930.xsd#fet_PropertyTaxesPayableNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-7813-a27e-267a8c675ee6" xlink:to="loc_fet_PropertyTaxesPayableNoncurrent_019fece9-9a07-7def-bb14-0ab63d3b896d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019fece9-9a07-765c-b042-a49a06126018" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesNoncurrent_019fece9-9a07-7813-a27e-267a8c675ee6" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019fece9-9a07-765c-b042-a49a06126018" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.firstenergycorp.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="fet-20260930.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:calculationLink xlink:role="http://www.firstenergycorp.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-7a90-8783-8d4d076e024d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_019fece9-9a07-773c-8223-4dccfd84418b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireProductiveAssets"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-7a90-8783-8d4d076e024d" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_019fece9-9a07-773c-8223-4dccfd84418b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRemovalCosts_019fece9-9a07-7405-98d7-faf7d5b3ba2e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForRemovalCosts"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-7a90-8783-8d4d076e024d" xlink:to="loc_us-gaap_PaymentsForRemovalCosts_019fece9-9a07-7405-98d7-faf7d5b3ba2e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_019fece9-9a07-725f-868a-fdee7455a11f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-7a90-8783-8d4d076e024d" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_019fece9-9a07-725f-868a-fdee7455a11f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromLoansReceivable_019fece9-9a07-7feb-90a3-d9d31cb43735" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsForProceedsFromLoansReceivable"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-7a90-8783-8d4d076e024d" xlink:to="loc_us-gaap_PaymentsForProceedsFromLoansReceivable_019fece9-9a07-7feb-90a3-d9d31cb43735" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_019fece9-9a07-79dc-a042-59508553eeb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromDivestitureOfInterestInJointVenture"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-7a90-8783-8d4d076e024d" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_019fece9-9a07-79dc-a042-59508553eeb3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fece9-9a07-7957-989a-7f4ce6258d64" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-795b-be6f-015f616ad39d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.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_019fece9-9a07-7957-989a-7f4ce6258d64" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-795b-be6f-015f616ad39d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7b3d-869b-470257bbcbab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fece9-9a07-7957-989a-7f4ce6258d64" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7b3d-869b-470257bbcbab" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-749f-9d2d-1d27db83ba6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019fece9-9a07-7957-989a-7f4ce6258d64" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019fece9-9a07-749f-9d2d-1d27db83ba6f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019fece9-9a07-731a-ae24-454b95b0fca4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_ProfitLoss_019fece9-9a07-731a-ae24-454b95b0fca4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_DepreciationDepletionAmortizationAndImpairments_019fece9-9a07-739f-9c5e-817bcd7cd9d5" xlink:href="fet-20260930.xsd#fet_DepreciationDepletionAmortizationAndImpairments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_fet_DepreciationDepletionAmortizationAndImpairments_019fece9-9a07-739f-9c5e-817bcd7cd9d5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_019fece9-9a07-79ed-92ef-e6e484147cdd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxesAndTaxCredits"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_019fece9-9a07-79ed-92ef-e6e484147cdd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_019fece9-9a07-7db6-a2ec-3421b38d5b1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions_019fece9-9a07-7db6-a2ec-3421b38d5b1e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_TransmissionRevenueCollectionNet_019fece9-9a07-73f2-b4c1-efb0b27868bd" xlink:href="fet-20260930.xsd#fet_TransmissionRevenueCollectionNet"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_fet_TransmissionRevenueCollectionNet_019fece9-9a07-73f2-b4c1-efb0b27868bd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables_019fece9-9a07-7eb3-9de6-faad27dcdfa6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables_019fece9-9a07-7eb3-9de6-faad27dcdfa6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019fece9-9a07-7c70-8db3-f5c29d43873d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_019fece9-9a07-7c70-8db3-f5c29d43873d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableTrade_019fece9-9a07-7f12-855c-77f073680b08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayableTrade"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableTrade_019fece9-9a07-7f12-855c-77f073680b08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_019fece9-9a07-7a23-bd2e-36034a98230c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_019fece9-9a07-7a23-bd2e-36034a98230c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_019fece9-9a07-7d25-992d-b7f6243a6890" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInInterestPayableNet"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_019fece9-9a07-7d25-992d-b7f6243a6890" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_019fece9-9a07-76a3-a207-276839a72c05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherCurrentLiabilities"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherCurrentLiabilities_019fece9-9a07-76a3-a207-276839a72c05" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_019fece9-9a07-7f2d-ae05-5442986c1e73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_019fece9-9a07-7f2d-ae05-5442986c1e73" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_019fece9-9a07-7ec3-855f-d8620ba2eb8c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:calculationArc order="13" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019fece9-9a07-7907-baba-56ec8578cd7a" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_019fece9-9a07-7ec3-855f-d8620ba2eb8c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7add-b853-81059fddac7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019fece9-9a07-771f-a283-2ae505a24a23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7add-b853-81059fddac7c" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_019fece9-9a07-771f-a283-2ae505a24a23" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromShortTermDebt_019fece9-9a07-795f-9b3e-f9e46ef8e662" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromShortTermDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7add-b853-81059fddac7c" xlink:to="loc_us-gaap_ProceedsFromShortTermDebt_019fece9-9a07-795f-9b3e-f9e46ef8e662" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_019fece9-9a07-765a-a096-dd88fc7349b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfLongTermDebt"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7add-b853-81059fddac7c" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_019fece9-9a07-765a-a096-dd88fc7349b6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_019fece9-9a07-7155-b376-d8215b76b9bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividends"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7add-b853-81059fddac7c" xlink:to="loc_us-gaap_PaymentsOfDividends_019fece9-9a07-7155-b376-d8215b76b9bc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_019fece9-9a07-709b-a1c8-d03f9021647c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7add-b853-81059fddac7c" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_019fece9-9a07-709b-a1c8-d03f9021647c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfShortTermDebt_019fece9-9a07-7577-91be-4bcb3eecdef0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfShortTermDebt"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019fece9-9a07-7add-b853-81059fddac7c" xlink:to="loc_us-gaap_RepaymentsOfShortTermDebt_019fece9-9a07-7577-91be-4bcb3eecdef0" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.firstenergycorp.com/role/REVENUEDetails" xlink:type="simple" xlink:href="fet-20260930.xsd#REVENUEDetails"/>
  <link:calculationLink xlink:role="http://www.firstenergycorp.com/role/REVENUEDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019fece9-9a07-7445-b69c-25d3aa20e9dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019fece9-9a07-72b8-bd4b-20ca71281556" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_019fece9-9a07-7445-b69c-25d3aa20e9dc" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019fece9-9a07-72b8-bd4b-20ca71281556" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueNotFromContractWithCustomer_019fece9-9a07-79ba-a61a-04ba5eaed0e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueNotFromContractWithCustomer"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_019fece9-9a07-7445-b69c-25d3aa20e9dc" xlink:to="loc_us-gaap_RevenueNotFromContractWithCustomer_019fece9-9a07-79ba-a61a-04ba5eaed0e3" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.firstenergycorp.com/role/INCOMETAXESScheduleofEffectiveIncomeTaxRateReconciliationDetails" xlink:type="simple" xlink:href="fet-20260930.xsd#INCOMETAXESScheduleofEffectiveIncomeTaxRateReconciliationDetails"/>
  <link:calculationLink xlink:role="http://www.firstenergycorp.com/role/INCOMETAXESScheduleofEffectiveIncomeTaxRateReconciliationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_019fece9-9a07-7ac9-890e-15c403865b01" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_019fece9-9a07-7ac9-890e-15c403865b01" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_019fece9-9a07-7388-9c8f-d2e3d438c663" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits_019fece9-9a07-7388-9c8f-d2e3d438c663" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityIncomePercent_019fece9-9a07-7029-965c-530cd76c29ac" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityIncomePercent"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityIncomePercent_019fece9-9a07-7029-965c-530cd76c29ac" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityDepreciationPercent_019fece9-9a07-7a26-b9fb-a39a508ef6a8" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityDepreciationPercent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityDepreciationPercent_019fece9-9a07-7a26-b9fb-a39a508ef6a8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationExcessDeferredTaxAmortizationPercent_019fece9-9a07-7f90-9e80-2311346de147" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationExcessDeferredTaxAmortizationPercent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationExcessDeferredTaxAmortizationPercent_019fece9-9a07-7f90-9e80-2311346de147" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationFederalAndStateRelatedFlowThroughPercent_019fece9-9a07-7726-bdc7-17e694e4d57f" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationFederalAndStateRelatedFlowThroughPercent"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationFederalAndStateRelatedFlowThroughPercent_019fece9-9a07-7726-bdc7-17e694e4d57f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent_019fece9-9a07-77e7-bc10-c203e8c50193" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent_019fece9-9a07-77e7-bc10-c203e8c50193" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_019fece9-9a07-7e57-96d1-032db1a90f50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_019fece9-9a07-7e57-96d1-032db1a90f50" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_019fece9-9a07-7ea6-b577-b83c83ec068c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_019fece9-9a07-7ea6-b577-b83c83ec068c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationRemeasurementOfExcessDeferredIncomeTaxesPercent_01a14476-59af-7771-aec8-0d977e58bea2" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationRemeasurementOfExcessDeferredIncomeTaxesPercent"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019fece9-9a07-7128-b707-8c7928231344" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationRemeasurementOfExcessDeferredIncomeTaxesPercent_01a14476-59af-7771-aec8-0d977e58bea2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_019fece9-9a07-796b-add3-2952a7fc4909" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_019fece9-9a07-796b-add3-2952a7fc4909" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxCredits_019fece9-9a07-7635-ac6c-9485cd10e286" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxReconciliationTaxCredits"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxCredits_019fece9-9a07-7635-ac6c-9485cd10e286" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityDepreciationAmount_019fece9-9a07-75dc-9182-71732c084d40" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityDepreciationAmount"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityDepreciationAmount_019fece9-9a07-75dc-9182-71732c084d40" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationExcessDeferredTaxAmortizationAmount_019fece9-9a07-7dc4-a31e-3e684755fb51" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationExcessDeferredTaxAmortizationAmount"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationExcessDeferredTaxAmortizationAmount_019fece9-9a07-7dc4-a31e-3e684755fb51" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationFederalAndStateRelatedFlowThroughAmount_019fece9-9a07-7bf8-8c7f-9df126ffa437" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationFederalAndStateRelatedFlowThroughAmount"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationFederalAndStateRelatedFlowThroughAmount_019fece9-9a07-7bf8-8c7f-9df126ffa437" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationOtherReconcilingItems_019fece9-9a07-71e8-bd4a-e80cbc752b15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxReconciliationOtherReconcilingItems"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_us-gaap_IncomeTaxReconciliationOtherReconcilingItems_019fece9-9a07-71e8-bd4a-e80cbc752b15" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxContingencies_019fece9-9a07-7c77-815a-1c50f1260d0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxReconciliationTaxContingencies"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxContingencies_019fece9-9a07-7c77-815a-1c50f1260d0e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_019fece9-9a07-7a1e-9b7a-0b4e34e2d364" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_019fece9-9a07-7a1e-9b7a-0b4e34e2d364" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationRemeasurementOfExcessDeferredIncomeTaxesAmount_01a14476-34d9-7328-a4cc-3ac5c45cd3e9" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationRemeasurementOfExcessDeferredIncomeTaxesAmount"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationRemeasurementOfExcessDeferredIncomeTaxesAmount_01a14476-34d9-7328-a4cc-3ac5c45cd3e9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityIncomeAmount_01a188d8-703e-7722-a23e-142dd4158e68" xlink:href="fet-20260930.xsd#fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityIncomeAmount"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefit_019fece9-9a07-7c75-b0f9-4f459641ae0a" xlink:to="loc_fet_EffectiveIncomeTaxRateReconciliationAllowanceForFundsUsedDuringConstructionEquityIncomeAmount_01a188d8-703e-7722-a23e-142dd4158e68" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
