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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2019-04-02</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001772812</rptOwnerCik>
            <rptOwnerName>Ryan Jason Michael</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1111 LOUISIANA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77002</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP &amp; General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13720</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Total includes (i) 1,466 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 2020, (ii) 1,532 RSUs previously awarded under the Plan and vesting in February 2021, and (iii) 2,163 RSUs previously awarded under the Plan and vesting in February 2022. The award to vest in 2020 shall vest if the Reporting Person continues to be an employee of Issuer from grant date through vesting date and on a pro-rata basis in the event of his earlier retirement, disability or death. The above awards to vest in 2021 and 2022 shall vest (i) if he continues to be an employee of Issuer from grant date through vesting date and (ii) in the event of his disability or death. Also, the above awards to vest in 2021 and 2022 shall vest on a pro-rata basis in the event of his retirement unless he satisfies various conditions for full vesting.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Vincent A. Mercaldi, Attorney-in-Fact</signatureName>
        <signatureDate>2019-04-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
