<?xml version="1.0" encoding="utf-8"?>
<linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.xbrl.org/2003/linkbase">
  <roleRef roleURI="http://nationalgridplc.com/xbrl/2021/roles/ProfitOrLoss" xlink:href="nationalgridplc-2022-03-31.xsd#ProfitOrLoss" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <roleRef roleURI="http://nationalgridplc.com/xbrl/2021/roles/StatementOfFinancialPosition" xlink:href="nationalgridplc-2022-03-31.xsd#StatementOfFinancialPosition" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <roleRef roleURI="http://nationalgridplc.com/xbrl/2021/roles/StatementOfCashFlows" xlink:href="nationalgridplc-2022-03-31.xsd#StatementOfCashFlows" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />
  <calculationLink xlink:role="http://nationalgridplc.com/xbrl/2021/roles/ProfitOrLoss" xlink:type="extended" xmlns:xlink="http://www.w3.org/1999/xlink">
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_NetGainsLossesInRespectOfCostOfHedging" xlink:label="nationalgridplc_NetGainsLossesInRespectOfCostOfHedging" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax" xlink:label="ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_NetLossesInRespectOfCashFlowHedgingOfCapitalExpenditure" xlink:label="nationalgridplc_NetLossesInRespectOfCashFlowHedgingOfCapitalExpenditure" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" xlink:label="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_ComprehensiveIncomeAttributableToEquityShareholdersOfTheParentFromDiscontinuedOperations" xlink:label="nationalgridplc_ComprehensiveIncomeAttributableToEquityShareholdersOfTheParentFromDiscontinuedOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncomeBeforeTaxHedgesOfNetInvestmentsInForeignOperations" xlink:label="ifrs-full_OtherComprehensiveIncomeBeforeTaxHedgesOfNetInvestmentsInForeignOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProfitLoss" xlink:label="ifrs-full_ProfitLoss" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ImpairmentLossImpairmentGainAndReversalOfImpairmentLossDeterminedInAccordanceWithIFRS9" xlink:label="ifrs-full_ImpairmentLossImpairmentGainAndReversalOfImpairmentLossDeterminedInAccordanceWithIFRS9" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_Revenue" xlink:label="ifrs-full_Revenue" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProfitLossFromDiscontinuedOperations" xlink:label="ifrs-full_ProfitLossFromDiscontinuedOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherOperatingIncomeExpense" xlink:label="ifrs-full_OtherOperatingIncomeExpense" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromDiscontinuedOperations" xlink:label="nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromDiscontinuedOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod" xlink:label="ifrs-full_ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ComprehensiveIncomeAttributableToOwnersOfParent" xlink:label="ifrs-full_ComprehensiveIncomeAttributableToOwnersOfParent" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProfitLossBeforeTax" xlink:label="ifrs-full_ProfitLossBeforeTax" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_FinanceCosts" xlink:label="ifrs-full_FinanceCosts" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProfitLossFromContinuingOperations" xlink:label="ifrs-full_ProfitLossFromContinuingOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLoss" xlink:label="ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLoss" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_FinanceIncome" xlink:label="ifrs-full_FinanceIncome" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ComprehensiveIncome" xlink:label="ifrs-full_ComprehensiveIncome" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncomeBeforeTaxCashFlowHedges" xlink:label="ifrs-full_OtherComprehensiveIncomeBeforeTaxCashFlowHedges" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IncomeTaxExpenseContinuingOperations" xlink:label="ifrs-full_IncomeTaxExpenseContinuingOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans" xlink:label="ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesFromInvestmentsInEquityInstruments" xlink:label="ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesFromInvestmentsInEquityInstruments" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss" xlink:label="ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncome" xlink:label="ifrs-full_OtherComprehensiveIncome" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProfitLossFromOperatingActivities" xlink:label="ifrs-full_ProfitLossFromOperatingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherComprehensiveIncomeBeforeTaxFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" xlink:label="ifrs-full_OtherComprehensiveIncomeBeforeTaxFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax" xlink:label="ifrs-full_ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromContinuingOperations" xlink:label="nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromContinuingOperations" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_ComprehensiveIncomeAttributableToEquityShareholdersOfTheParentFromContinuingOperations" xlink:label="nationalgridplc_ComprehensiveIncomeAttributableToEquityShareholdersOfTheParentFromContinuingOperations" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossFromOperatingActivities" xlink:to="ifrs-full_Revenue" order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossFromOperatingActivities" xlink:to="ifrs-full_ImpairmentLossImpairmentGainAndReversalOfImpairmentLossDeterminedInAccordanceWithIFRS9" order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossFromOperatingActivities" xlink:to="ifrs-full_OtherOperatingIncomeExpense" order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossBeforeTax" xlink:to="ifrs-full_ProfitLossFromOperatingActivities" order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossBeforeTax" xlink:to="ifrs-full_FinanceIncome" order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossBeforeTax" xlink:to="ifrs-full_FinanceCosts" order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossBeforeTax" xlink:to="ifrs-full_ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod" order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossFromContinuingOperations" xlink:to="ifrs-full_ProfitLossBeforeTax" order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLossFromContinuingOperations" xlink:to="ifrs-full_IncomeTaxExpenseContinuingOperations" order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLoss" xlink:to="ifrs-full_ProfitLossFromContinuingOperations" order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ProfitLoss" xlink:to="ifrs-full_ProfitLossFromDiscontinuedOperations" order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans" order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_OtherComprehensiveIncomeBeforeTaxGainsLossesFromInvestmentsInEquityInstruments" order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax" xlink:to="nationalgridplc_NetLossesInRespectOfCashFlowHedgingOfCapitalExpenditure" order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLoss" order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_OtherComprehensiveIncomeBeforeTaxHedgesOfNetInvestmentsInForeignOperations" order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_OtherComprehensiveIncomeBeforeTaxCashFlowHedges" order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" xlink:to="nationalgridplc_NetGainsLossesInRespectOfCostOfHedging" order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_OtherComprehensiveIncomeBeforeTaxFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome" order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax" order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" xlink:to="ifrs-full_IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss" order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncome" xlink:to="nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromContinuingOperations" order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_OtherComprehensiveIncome" xlink:to="nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromDiscontinuedOperations" order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ComprehensiveIncome" xlink:to="ifrs-full_OtherComprehensiveIncome" order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ComprehensiveIncome" xlink:to="ifrs-full_ProfitLossFromContinuingOperations" order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ComprehensiveIncome" xlink:to="ifrs-full_ProfitLossFromDiscontinuedOperations" order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromContinuingOperations" xlink:to="ifrs-full_OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax" order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="nationalgridplc_OtherComprehensiveIncomeLossForTheYearNetOfTaxFromContinuingOperations" xlink:to="ifrs-full_OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax" order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ComprehensiveIncomeAttributableToOwnersOfParent" xlink:to="nationalgridplc_ComprehensiveIncomeAttributableToEquityShareholdersOfTheParentFromContinuingOperations" order="28" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_ComprehensiveIncomeAttributableToOwnersOfParent" xlink:to="nationalgridplc_ComprehensiveIncomeAttributableToEquityShareholdersOfTheParentFromDiscontinuedOperations" order="29" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:role="http://nationalgridplc.com/xbrl/2021/roles/StatementOfFinancialPosition" xlink:type="extended" xmlns:xlink="http://www.w3.org/1999/xlink">
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IntangibleAssetsOtherThanGoodwill" xlink:label="ifrs-full_IntangibleAssetsOtherThanGoodwill" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_Inventories" xlink:label="ifrs-full_Inventories" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_InvestmentAccountedForUsingEquityMethod" xlink:label="ifrs-full_InvestmentAccountedForUsingEquityMethod" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentProvisions" xlink:label="ifrs-full_CurrentProvisions" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentTaxAssets" xlink:label="ifrs-full_CurrentTaxAssets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ShorttermBorrowings" xlink:label="ifrs-full_ShorttermBorrowings" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentDerivativeFinancialLiabilities" xlink:label="ifrs-full_NoncurrentDerivativeFinancialLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_Liabilities" xlink:label="ifrs-full_Liabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentRecognisedAssetsDefinedBenefitPlan" xlink:label="ifrs-full_NoncurrentRecognisedAssetsDefinedBenefitPlan" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherNoncurrentAssets" xlink:label="ifrs-full_OtherNoncurrentAssets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncontrollingInterests" xlink:label="ifrs-full_NoncontrollingInterests" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_LongtermBorrowings" xlink:label="ifrs-full_LongtermBorrowings" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_TradeAndOtherCurrentReceivables" xlink:label="ifrs-full_TradeAndOtherCurrentReceivables" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSaleOrAsHeldForDistributionToOwners" xlink:label="ifrs-full_NoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSaleOrAsHeldForDistributionToOwners" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherNoncurrentFinancialAssets" xlink:label="ifrs-full_OtherNoncurrentFinancialAssets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentLiabilities" xlink:label="ifrs-full_CurrentLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherEquityInterest" xlink:label="ifrs-full_OtherEquityInterest" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_PropertyPlantAndEquipment" xlink:label="ifrs-full_PropertyPlantAndEquipment" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_SharePremium" xlink:label="ifrs-full_SharePremium" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_LiabilitiesIncludedInDisposalGroupsClassifiedAsHeldForSale" xlink:label="ifrs-full_LiabilitiesIncludedInDisposalGroupsClassifiedAsHeldForSale" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentContractLiabilities" xlink:label="ifrs-full_CurrentContractLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentTaxLiabilities" xlink:label="ifrs-full_CurrentTaxLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NetAssetsLiabilities" xlink:label="ifrs-full_NetAssetsLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentDerivativeFinancialLiabilities" xlink:label="ifrs-full_CurrentDerivativeFinancialLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentAssets" xlink:label="ifrs-full_CurrentAssets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentAssets" xlink:label="ifrs-full_NoncurrentAssets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_DeferredTaxLiabilities" xlink:label="ifrs-full_DeferredTaxLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherCurrentFinancialAssets" xlink:label="ifrs-full_OtherCurrentFinancialAssets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentDerivativeFinancialAssets" xlink:label="ifrs-full_NoncurrentDerivativeFinancialAssets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentProvisions" xlink:label="ifrs-full_NoncurrentProvisions" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentLiabilities" xlink:label="ifrs-full_NoncurrentLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IssuedCapital" xlink:label="ifrs-full_IssuedCapital" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentRecognisedLiabilitiesDefinedBenefitPlan" xlink:label="ifrs-full_NoncurrentRecognisedLiabilitiesDefinedBenefitPlan" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_Equity" xlink:label="ifrs-full_Equity" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherNoncurrentLiabilities" xlink:label="ifrs-full_OtherNoncurrentLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_TradeAndOtherCurrentPayables" xlink:label="ifrs-full_TradeAndOtherCurrentPayables" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashAndCashEquivalents" xlink:label="ifrs-full_CashAndCashEquivalents" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_Goodwill" xlink:label="ifrs-full_Goodwill" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_RetainedEarnings" xlink:label="ifrs-full_RetainedEarnings" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_NoncurrentContractLiabilities" xlink:label="ifrs-full_NoncurrentContractLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_Assets" xlink:label="ifrs-full_Assets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_EquityAttributableToOwnersOfParent" xlink:label="ifrs-full_EquityAttributableToOwnersOfParent" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CurrentDerivativeFinancialAssets" xlink:label="ifrs-full_CurrentDerivativeFinancialAssets" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_Goodwill" order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_IntangibleAssetsOtherThanGoodwill" order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_PropertyPlantAndEquipment" order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_OtherNoncurrentAssets" order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_NoncurrentRecognisedAssetsDefinedBenefitPlan" order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_OtherNoncurrentFinancialAssets" order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_InvestmentAccountedForUsingEquityMethod" order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentAssets" xlink:to="ifrs-full_NoncurrentDerivativeFinancialAssets" order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentAssets" xlink:to="ifrs-full_Inventories" order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentAssets" xlink:to="ifrs-full_TradeAndOtherCurrentReceivables" order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentAssets" xlink:to="ifrs-full_CurrentTaxAssets" order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentAssets" xlink:to="ifrs-full_OtherCurrentFinancialAssets" order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentAssets" xlink:to="ifrs-full_CurrentDerivativeFinancialAssets" order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentAssets" xlink:to="ifrs-full_CashAndCashEquivalents" order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentAssets" xlink:to="ifrs-full_NoncurrentAssetsOrDisposalGroupsClassifiedAsHeldForSaleOrAsHeldForDistributionToOwners" order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_Assets" xlink:to="ifrs-full_CurrentAssets" order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_Assets" xlink:to="ifrs-full_NoncurrentAssets" order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentLiabilities" xlink:to="ifrs-full_LongtermBorrowings" order="33" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentLiabilities" xlink:to="ifrs-full_NoncurrentDerivativeFinancialLiabilities" order="34" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentLiabilities" xlink:to="ifrs-full_OtherNoncurrentLiabilities" order="35" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentLiabilities" xlink:to="ifrs-full_NoncurrentContractLiabilities" order="36" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentLiabilities" xlink:to="ifrs-full_DeferredTaxLiabilities" order="37" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentLiabilities" xlink:to="ifrs-full_NoncurrentRecognisedLiabilitiesDefinedBenefitPlan" order="38" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NoncurrentLiabilities" xlink:to="ifrs-full_NoncurrentProvisions" order="39" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentLiabilities" xlink:to="ifrs-full_ShorttermBorrowings" order="24" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentLiabilities" xlink:to="ifrs-full_CurrentDerivativeFinancialLiabilities" order="25" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentLiabilities" xlink:to="ifrs-full_TradeAndOtherCurrentPayables" order="26" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentLiabilities" xlink:to="ifrs-full_CurrentContractLiabilities" order="27" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentLiabilities" xlink:to="ifrs-full_CurrentTaxLiabilities" order="28" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentLiabilities" xlink:to="ifrs-full_CurrentProvisions" order="29" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CurrentLiabilities" xlink:to="ifrs-full_LiabilitiesIncludedInDisposalGroupsClassifiedAsHeldForSale" order="30" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_Liabilities" xlink:to="ifrs-full_NoncurrentLiabilities" order="40" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_Liabilities" xlink:to="ifrs-full_CurrentLiabilities" order="31" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NetAssetsLiabilities" xlink:to="ifrs-full_Liabilities" order="41" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_NetAssetsLiabilities" xlink:to="ifrs-full_Assets" order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_EquityAttributableToOwnersOfParent" xlink:to="ifrs-full_IssuedCapital" order="44" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_EquityAttributableToOwnersOfParent" xlink:to="ifrs-full_SharePremium" order="45" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_EquityAttributableToOwnersOfParent" xlink:to="ifrs-full_RetainedEarnings" order="46" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_EquityAttributableToOwnersOfParent" xlink:to="ifrs-full_OtherEquityInterest" order="47" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_Equity" xlink:to="ifrs-full_EquityAttributableToOwnersOfParent" order="48" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_Equity" xlink:to="ifrs-full_NoncontrollingInterests" order="49" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:role="http://nationalgridplc.com/xbrl/2021/roles/StatementOfCashFlows" xlink:type="extended" xmlns:xlink="http://www.w3.org/1999/xlink">
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_AdjustmentsForCashFlowsRelatingToExceptionalItems" xlink:label="nationalgridplc_AdjustmentsForCashFlowsRelatingToExceptionalItems" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_PaymentsToAcquireOrRedeemEntitysShares" xlink:label="ifrs-full_PaymentsToAcquireOrRedeemEntitysShares" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_RepaymentsOfBorrowingsClassifiedAsFinancingActivities" xlink:label="ifrs-full_RepaymentsOfBorrowingsClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProceedsFromSalesOrMaturityOfFinancialInstrumentsClassifiedAsInvestingActivities" xlink:label="ifrs-full_ProceedsFromSalesOrMaturityOfFinancialInstrumentsClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_AdjustmentsForFairValueGainsLosses" xlink:label="ifrs-full_AdjustmentsForFairValueGainsLosses" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProceedsFromBorrowingsClassifiedAsFinancingActivities" xlink:label="ifrs-full_ProceedsFromBorrowingsClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_CashInflowsOnDerivativesClassifiedAsFinancingActivities" xlink:label="nationalgridplc_CashInflowsOnDerivativesClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" xlink:label="ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherCashPaymentsToAcquireInterestsInJointVenturesClassifiedAsInvestingActivities" xlink:label="ifrs-full_OtherCashPaymentsToAcquireInterestsInJointVenturesClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_InterestPaidClassifiedAsFinancingActivities" xlink:label="ifrs-full_InterestPaidClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:label="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_CashOutflowsOnDerivativesClassifiedAsFinancingActivities" xlink:label="nationalgridplc_CashOutflowsOnDerivativesClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_PurchaseOfFinancialInstrumentsClassifiedAsInvestingActivities" xlink:label="ifrs-full_PurchaseOfFinancialInstrumentsClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInInvestingActivitiesDiscontinuedOperations" xlink:label="ifrs-full_CashFlowsFromUsedInInvestingActivitiesDiscontinuedOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_InterestReceivedClassifiedAsInvestingActivities" xlink:label="ifrs-full_InterestReceivedClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_DividendsPaidClassifiedAsFinancingActivities" xlink:label="ifrs-full_DividendsPaidClassifiedAsFinancingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" xlink:label="ifrs-full_PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_AdjustmentsForSharebasedPayments" xlink:label="ifrs-full_AdjustmentsForSharebasedPayments" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInOperatingActivitiesDiscontinuedOperations" xlink:label="ifrs-full_CashFlowsFromUsedInOperatingActivitiesDiscontinuedOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_PurchaseOfInterestsInInvestmentsAccountedForUsingEquityMethod" xlink:label="ifrs-full_PurchaseOfInterestsInInvestmentsAccountedForUsingEquityMethod" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:label="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashPaymentsForFutureContractsForwardContractsOptionContractsAndSwapContractsClassifiedAsInvestingActivities" xlink:label="ifrs-full_CashPaymentsForFutureContractsForwardContractsOptionContractsAndSwapContractsClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_AdjustmentsForDepreciationAndAmortisationExpenseAndImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss" xlink:label="ifrs-full_AdjustmentsForDepreciationAndAmortisationExpenseAndImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_AdjustmentsForExceptionalItemsAndRemeasurements" xlink:label="nationalgridplc_AdjustmentsForExceptionalItemsAndRemeasurements" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities" xlink:label="ifrs-full_CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInIncreaseDecreaseInCurrentBorrowings" xlink:label="ifrs-full_CashFlowsFromUsedInIncreaseDecreaseInCurrentBorrowings" />
    <loc xlink:type="locator" xlink:href="nationalgridplc-2022-03-31.xsd#nationalgridplc_NetMovementsInShortTermFinancialInvestmentsClassifiedAsInvestingActivities" xlink:label="nationalgridplc_NetMovementsInShortTermFinancialInvestmentsClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IncomeTaxesPaidRefundClassifiedAsOperatingActivities" xlink:label="ifrs-full_IncomeTaxesPaidRefundClassifiedAsOperatingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" xlink:label="ifrs-full_ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_OtherCashReceiptsFromSalesOfInterestsInJointVenturesClassifiedAsInvestingActivities" xlink:label="ifrs-full_OtherCashReceiptsFromSalesOfInterestsInJointVenturesClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_DividendsReceivedFromInvestmentsAccountedForUsingEquityMethodClassifiedAsInvestingActivities" xlink:label="ifrs-full_DividendsReceivedFromInvestmentsAccountedForUsingEquityMethodClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_AdjustmentsForIncreaseDecreaseInEmployeeBenefitLiabilities" xlink:label="ifrs-full_AdjustmentsForIncreaseDecreaseInEmployeeBenefitLiabilities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInOperations" xlink:label="ifrs-full_CashFlowsFromUsedInOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInFinancingActivitiesDiscontinuedOperations" xlink:label="ifrs-full_CashFlowsFromUsedInFinancingActivitiesDiscontinuedOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProfitLossFromOperatingActivities" xlink:label="ifrs-full_ProfitLossFromOperatingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashFlowsFromUsedInOperatingActivitiesContinuingOperations" xlink:label="ifrs-full_CashFlowsFromUsedInOperatingActivitiesContinuingOperations" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProceedsFromSalesOfInterestsInAssociates" xlink:label="ifrs-full_ProceedsFromSalesOfInterestsInAssociates" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_CashReceiptsFromFutureContractsForwardContractsOptionContractsAndSwapContractsClassifiedAsInvestingActivities" xlink:label="ifrs-full_CashReceiptsFromFutureContractsForwardContractsOptionContractsAndSwapContractsClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_AdjustmentsForProvisions" xlink:label="ifrs-full_AdjustmentsForProvisions" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_IncreaseDecreaseInWorkingCapital" xlink:label="ifrs-full_IncreaseDecreaseInWorkingCapital" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_PurchaseOfIntangibleAssetsClassifiedAsInvestingActivities" xlink:label="ifrs-full_PurchaseOfIntangibleAssetsClassifiedAsInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_ProceedsFromSaleOrIssueOfTreasuryShares" xlink:label="ifrs-full_ProceedsFromSaleOrIssueOfTreasuryShares" />
    <loc xlink:type="locator" xlink:href="http://xbrl.ifrs.org/taxonomy/2020-03-16/full_ifrs/full_ifrs-cor_2020-03-16.xsd#ifrs-full_PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities" xlink:label="ifrs-full_PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperatingActivitiesContinuingOperations" xlink:to="ifrs-full_CashFlowsFromUsedInOperations" order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperatingActivitiesContinuingOperations" xlink:to="ifrs-full_IncomeTaxesPaidRefundClassifiedAsOperatingActivities" order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_PurchaseOfFinancialInstrumentsClassifiedAsInvestingActivities" order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_OtherCashPaymentsToAcquireInterestsInJointVenturesClassifiedAsInvestingActivities" order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_CashFlowsUsedInObtainingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities" order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_PurchaseOfInterestsInInvestmentsAccountedForUsingEquityMethod" order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_ProceedsFromSalesOrMaturityOfFinancialInstrumentsClassifiedAsInvestingActivities" order="23" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_ProceedsFromSalesOfInterestsInAssociates" order="24" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_OtherCashReceiptsFromSalesOfInterestsInJointVenturesClassifiedAsInvestingActivities" order="25" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_PurchaseOfIntangibleAssetsClassifiedAsInvestingActivities" order="26" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" order="27" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities" order="28" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_DividendsReceivedFromInvestmentsAccountedForUsingEquityMethodClassifiedAsInvestingActivities" order="29" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_InterestReceivedClassifiedAsInvestingActivities" order="30" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="nationalgridplc_NetMovementsInShortTermFinancialInvestmentsClassifiedAsInvestingActivities" order="31" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_CashReceiptsFromFutureContractsForwardContractsOptionContractsAndSwapContractsClassifiedAsInvestingActivities" order="32" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" xlink:to="ifrs-full_CashPaymentsForFutureContractsForwardContractsOptionContractsAndSwapContractsClassifiedAsInvestingActivities" order="33" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_ProceedsFromSaleOrIssueOfTreasuryShares" order="37" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_PaymentsToAcquireOrRedeemEntitysShares" order="38" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_ProceedsFromBorrowingsClassifiedAsFinancingActivities" order="39" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_RepaymentsOfBorrowingsClassifiedAsFinancingActivities" order="40" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_PaymentsOfLeaseLiabilitiesClassifiedAsFinancingActivities" order="41" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_CashFlowsFromUsedInIncreaseDecreaseInCurrentBorrowings" order="42" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="nationalgridplc_CashInflowsOnDerivativesClassifiedAsFinancingActivities" order="43" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="nationalgridplc_CashOutflowsOnDerivativesClassifiedAsFinancingActivities" order="44" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_InterestPaidClassifiedAsFinancingActivities" order="45" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" xlink:to="ifrs-full_DividendsPaidClassifiedAsFinancingActivities" order="46" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" xlink:to="ifrs-full_CashFlowsFromUsedInFinancingActivitiesContinuingOperations" order="47" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" xlink:to="ifrs-full_CashFlowsFromUsedInFinancingActivitiesDiscontinuedOperations" order="48" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" xlink:to="ifrs-full_CashFlowsFromUsedInInvestingActivitiesContinuingOperations" order="34" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" xlink:to="ifrs-full_CashFlowsFromUsedInInvestingActivitiesDiscontinuedOperations" order="35" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" xlink:to="ifrs-full_CashFlowsFromUsedInOperatingActivitiesContinuingOperations" order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_IncreaseDecreaseInCashAndCashEquivalentsBeforeEffectOfExchangeRateChanges" xlink:to="ifrs-full_CashFlowsFromUsedInOperatingActivitiesDiscontinuedOperations" order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="ifrs-full_ProfitLossFromOperatingActivities" order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="nationalgridplc_AdjustmentsForExceptionalItemsAndRemeasurements" order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="ifrs-full_AdjustmentsForFairValueGainsLosses" order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="ifrs-full_AdjustmentsForDepreciationAndAmortisationExpenseAndImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss" order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="ifrs-full_AdjustmentsForSharebasedPayments" order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="ifrs-full_IncreaseDecreaseInWorkingCapital" order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="-1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="ifrs-full_AdjustmentsForProvisions" order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="ifrs-full_AdjustmentsForIncreaseDecreaseInEmployeeBenefitLiabilities" order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
    <calculationArc xlink:type="arc" xlink:from="ifrs-full_CashFlowsFromUsedInOperations" xlink:to="nationalgridplc_AdjustmentsForCashFlowsRelatingToExceptionalItems" order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" priority="1" weight="1.0" />
  </calculationLink>
</linkbase>