Formatting Issues

How to Add Double Underlines in Microsoft Word Equation Editor

Kushani Nimanthika Oct 14, 2026 870 views

Question details

The user is looking for a way to add double continuous lines under or over equations in Microsoft Word to clearly highlight final mathematical answers.

How to Add Double Underlines in Microsoft Word Equation Editor

Product: Microsoft Word Equation Editor
Device & OS: not provided
Scenario: Typing and formatting mathematical equations, specifically aiming to emphasize final calculation results.
Observed behavior: Microsoft Word's native Equation Editor does not include a built-in double underline or double overbar command, making it difficult to format final answers with two continuous lines.

Before you start

Verify that you are using the built-in Microsoft Word Equation Editor rather than a third-party add-in like MathType, as the available features and workarounds will differ significantly.

Solution 1Recommended

Use Alternative Formatting to Highlight Equations

Since a native double underline command is missing, you can use alternative formatting techniques within the Equation Editor to emphasize your final mathematical answers.

While standard text in Word supports double underlining, applying this formatting directly inside the Equation block often results in broken or misaligned lines. Instead, users must rely on alternative visual indicators or manual formatting.

Insert your equation

Navigate to the 'Insert' tab on the ribbon and click 'Equation', or use the keyboard shortcut 'Alt' + '=' to open a new equation block.

Apply a single underbar or box

Select the portion of the equation you want to highlight. Under the 'Equation' tab, click on the 'Accent' menu and choose the single 'Underbar' option. Alternatively, use the 'Enclose' function to place a box around your final answer.

Change the font color or weight

To make the final answer stand out without relying on a double underline, highlight the final equation text, navigate to the 'Home' tab, and apply a bold font weight or a distinct text color.

Use Alternative Formatting to Highlight Equations

Submit a Feature Request: You can request official support for double underlines and double overbars in the Equation Editor by submitting feedback through the Microsoft Feedback Portal at https://feedbackportal.microsoft.com/feedback.

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Frequently Asked Questions

Is there a keyboard shortcut for double underline in Word Equation Editor?

No. Because Microsoft Word's Equation Editor does not currently support a dedicated double underline or double overbar command, there is no keyboard shortcut available for this specific action.

Can I use the standard text double underline (Ctrl+Shift+D) for equations?

While you can technically apply the standard double underline shortcut to regular text outside the editor, applying it to elements inside the Equation Editor block often fails to render correctly, causing broken or misaligned lines.

Are there third-party tools that support double underlines for math equations?

Yes. Third-party equation add-ins like MathType offer far more advanced mathematical formatting options, including native support for double underlines and double overbars, which can be integrated directly into Microsoft Word.

Document & File Issues