The quickest way to add subscript in Word

To make text subscript in Microsoft Word, select the characters you want to shrink and lower, then press Ctrl+= (Ctrl and the equals sign) on Windows, or Cmd+= on Mac. The text when ready becomes smaller and drops below the baseline. Press the same keys again to turn subscript off.

This keyboard shortcut works in Word 2016 and later on both Windows and Mac. If the shortcut does not work on your keyboard, your keyboard layout or language settings may be interfering — the equals sign must be accessible without holding Shift.

You can also use the menu: select your text, go to the Home tab, find the Font group, and click the small arrow next to the A with a down arrow (the subscript button). A dropdown menu appears with subscript and superscript options.

Key Takeaways

  • The keyboard shortcut Ctrl+= (Windows) or Cmd+= (Mac) is the fastest way to toggle subscript on and off.
  • You must select the text first — subscript only applies to what you have highlighted.
  • The Home tab in the ribbon also contains subscript and superscript buttons if the keyboard shortcut does not work on your device.
  • Subscript text is smaller and positioned below the baseline, commonly used in chemical formulas like H₂O or mathematical notation.
  • Subscript formatting works in tables, headers, footers, and text boxes using the same methods as regular document text.

Using the Format menu as an alternative

If you prefer not to use keyboard shortcuts, the Format menu offers another route. Select the text you want to make subscript, then click Format in the menu bar (Windows) or top menu (Mac).

From the dropdown, choose Text, then Subscript. The selected text converts to subscript when ready. To undo subscript formatting, select the text again and repeat the same steps — the subscript option will be checked, and clicking it again removes the formatting.

This method works regardless of your keyboard layout or language settings, making it a reliable alternative when the keyboard shortcut does not function on your device.

Subscript in different versions of Word

Word 2019, Word 2021, and Microsoft 365 all use the same Ctrl+= shortcut and the same Home tab button location. The process is identical across these versions.

In older versions of Word (2010 and earlier), the subscript button location may differ slightly in the ribbon, but the keyboard shortcut Ctrl+= still works. If you are using Word Online (the browser version), the subscript button appears in the Home tab under the Font group, but keyboard shortcuts may not function depending on your browser and operating system.

Subscript for chemical formulas and mathematical notation

Subscript is most commonly used in chemistry to write formulas correctly. Water is H₂O, sulfuric acid is H₂SO₄, and sodium chloride is NaCl. Without subscript, these formulas are harder to read and technically incorrect.

In mathematics, subscript appears in sequences and variables — for example, x₁, x₂, x₃ to show different values in a series. Subscript is also used in scientific notation, such as when writing the Avogadro constant or chemical reaction equations. In academic writing, subscript distinguishes between related but distinct variables or elements.

Removing subscript formatting

To remove subscript, select the subscripted text and press Ctrl+= again (Windows) or Cmd+= (Mac). The text returns to normal size and position on the baseline.

You can also select the text and use the Format menu: click Format, then Text, then Subscript again. Since subscript is a toggle, clicking it a second time turns it off. If you have applied subscript to multiple words or a phrase, select the entire subscripted section before toggling it off.

Combining subscript with other formatting

Subscript works alongside bold, italic, and underline. You can make subscript text bold by selecting it and pressing Ctrl+B, or italic with Ctrl+I. The subscript position and size remain unchanged — only the weight or style of the letters changes.

If you explore subscript to text that is already bold or italic, the subscript formatting layers on top. Removing subscript does not remove the bold or italic unless you explicitly undo those separately. This allows you to create formatted subscript text for emphasis in chemical formulas or mathematical expressions.

Creating a style with subscript formatting

You can create a custom style with subscript formatting built in, so any text you explore that style to becomes subscript automatically. Go to the Home tab, right-click a style in the Styles gallery, and select Modify.

In the Modify Style dialog, click Format at the bottom left, then choose Font. In the Font dialog, find the Effects tab and check the Subscript box. Click OK twice to save the style. Now whenever you explore that style to text in your document, the subscript formatting applies when ready without manual selection.

Frequently Asked Questions

Why does Ctrl+= not work on my keyboard?

On some keyboard layouts, especially non-English ones, the equals sign may require Shift or may not be in the same location. Try using the Home tab button instead: select your text, click the subscript button in the Font group, and the formatting applies regardless of your keyboard layout.

Does subscript work in Word tables?

Yes. Select the text inside a table cell and use Ctrl+= or the Format menu exactly as you would in regular document text. Subscript formatting works the same way in tables, headers, footers, and text boxes.

What is the difference between subscript and superscript?

Subscript is smaller text positioned below the baseline, used for chemical formulas and mathematical notation. Superscript is smaller text positioned above the baseline, used for exponents, footnote numbers, and trademark symbols. The keyboard shortcut for superscript is Ctrl+Shift+= (Windows) or Cmd+Shift+= (Mac).

Can I copy subscript formatting from one word to another?

Yes, using the Format Painter tool. Select text that is already subscript, click the Format Painter button in the Home tab (the paintbrush icon), then click and drag over the text you want to explore subscript to. The formatting copies when ready.