<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-07-28</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001130310</issuerCik>
        <issuerName>CENTERPOINT ENERGY INC</issuerName>
        <issuerTradingSymbol>CNP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001817841</rptOwnerCik>
            <rptOwnerName>Karuturi Monica</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1111 LOUISIANA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP and General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14997</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Total includes (i) 1,395 time-based restricted stock units (&quot;RSUs&quot;) previously awarded under the Issuer's Long-term Incentive Plan (the &quot;Plan&quot;) and vesting in February 2021, (ii) 1,243 RSUs previously awarded under the Plan and vesting in February 2022, and (iii) 1,911 RSUs previously awarded under the Plan and vesting in February 2023. The above awards shall vest (i) if the Reporting Person continues to be an employee of Issuer from grant date through vesting date and (ii) in the event of her disability or death.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Vincent A. Mercaldi, Attorney-in-Fact</signatureName>
        <signatureDate>2020-07-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
