Servicesbreadcrumb separatoreditHelp!breadcrumb separatorTo help you in your workbreadcrumb separatorFurther resourcesbreadcrumb separatorMathematical formulaebreadcrumb separatorEquation editor

Equation(s) 

  • What changed since “Equation Editor® 3.0”
    • Microsoft removed Equation Editor 3.0 from Office in the January 2018 Public Update due to security vulnerabilities. Microsoft Support+2Microsoft Learn+2
    • In newer versions (Office 2016, 2019, Microsoft 365, etc.), a modern built-in equation editor is used, based on OMML (Office Math Markup Language). Microsoft Support+2Microsoft Learn+2
    • Existing equations created with the old Equation Editor 3.0 can still display, but editing them using the old tool is no longer supported. If you try, you may get an error like: “Microsoft Equation is not available.” GitHub+2Microsoft Learn+2
    • To edit old 3.0 equations, you need to convert them to the newer format (OMML), or use third‑party tools like MathType (by WIRIS) which can handle the conversion and editing. Microsoft Support+2GitHub+2
    Converting old equations to OMML In modern Office versions (Office 2019, Microsoft 365, etc.):
    • You can double-click an old equation or select it, and press Enter, which triggers a conversion dialog (if your Office build supports it). Microsoft Support
    • The conversion works best when the document is in the newer file format (e.g. .docx rather than old .doc). Microsoft Support+1
    • After conversion, the equation becomes editable with the built-in equation tools. Microsoft Support
    If conversion is not possible, MathType can help by enabling editing of the old-style equations. GitHub+1 Step-by-Step Guide: Convert Equation Editor 3.0 Equations to Modern Format (OMML) 1. Identify the old equations
    • Open your Word document.
    • Look for equations that you can’t edit (they often behave like images or objects).
    • When you try to double-click them, nothing happens, or you might see an error like:
    "Microsoft Equation is not available." These are likely Equation Editor 3.0 objects.
    2. Convert old equations (if the built-in converter is available) Method A: Try the built-in converter
    1. Click once on the old equation.
    2. Press Enter or right-click > Convert (if the option is visible).
    3. If Word® prompts:
    “This equation was created using an older version. Do you want to convert it?”
    Click Yes.
    1. The equation will be converted to the new OMML format, and you can now edit it using the modern equation tools.
    3. If conversion doesn't work: Use MathType (third-party tool) If Word doesn't offer to convert, or gives an error:
    1. Download and install MathType by WIRIS .
      • It offers a free trial.
    2. After installing, open your Word document.
    3. Click the MathType tab that appears in the ribbon.
    4. Select the equation object, then choose:
    MathType > Convert Equations
    1. You can choose to:
      • Convert to MathType format (still editable).
      • Or to Office math (OMML) if you want to use Word’s built-in tools.
    ⚠️ Important
    • If your document is in .doc format, save it first as a .docx file.
      • Go to File > Save As > Word ® Document (*.docx).
    • Old-style equations often do not print well or export correctly to PDF — so conversion is highly recommended.
    • Once converted, you can insert/edit new equations via:
    Insert > Equation or press Alt + =
    Bonus Tip: Check if you are using the right Office ® version To access modern equation support:
    • Use Office 2016, 2019, 2021, or Microsoft 365®
    • Version should be Build 16.0.8528.2139 or higher
      • Check via: File > Account > About Word