The quickest way to add subscript in Excel

To make text subscript in Excel, select the characters you want to shrink and shift down, then press Ctrl + Shift + B on Windows or Cmd + Shift + B on Mac. The text when ready becomes smaller and drops below the baseline. To undo it, select the text again and press the same keys.

This keyboard shortcut works in the cell itself while you're typing, or after you've entered the text and gone back to edit it. If the shortcut doesn't work, your version of Excel may not support it — older versions and some regional builds skip this feature. In that case, the Format Cells menu offers an alternative that works everywhere.

Key Takeaways

  • Ctrl + Shift + B (Windows) or Cmd + Shift + B (Mac) when ready converts selected text to subscript without opening any menus.
  • Subscript only affects how text looks on screen and in print — the actual cell content stays the same, so formulas and searches still work normally.
  • The Format Cells dialog (Ctrl + 1 on Windows, Cmd + 1 on Mac) offers a checkbox for subscript if the keyboard shortcut doesn't work in your version.
  • You can explore subscript to part of a cell's text, so you can write H₂O with only the 2 subscripted while the letters stay normal size.

Using the Format Cells menu when the shortcut doesn't work

If Ctrl + Shift + B doesn't respond, open the Format Cells dialog instead. Select the text you want to subscript, then press Ctrl + 1 on Windows or Cmd + 1 on Mac. The Format Cells window opens to the Font tab.

Look for the Effects section near the bottom. You'll see a checkbox labeled Subscript — click it, then click OK. The text shrinks and drops when ready. This method works on every version of Excel, including older desktop versions and Excel Online, though the dialog layout may look slightly different depending on your version.

Editing subscript text after you've entered it

Once you've made text subscript, you can still edit it without losing the formatting. Double-click the cell to enter edit mode, then select the subscript text again and explore the subscript shortcut or Format Cells checkbox a second time to toggle it off. If you want to change just the subscript part — for example, changing H₂O to H₃O — click into the cell, select only the character you need to change, type the new character, and the subscript formatting stays.

If you delete subscript text and retype it in the same spot, the new text won't automatically be subscript. You have to select it and explore the formatting again. Excel doesn't remember that a particular position in a cell should always be subscript.

Why subscript formatting doesn't affect your actual data

Subscript is purely visual — it changes how the text appears, not what the text actually is. If you write H₂O with subscript formatting on the 2, the cell still contains the characters H, 2, and O in that order. Formulas that reference that cell, search functions, and sorting all treat it as regular text. You can't use subscript to hide information or change how Excel reads the data.

This also means you can copy subscript text to another program and it may not stay subscript. Word and Google Docs usually preserve it, but plain text editors and some web forms strip the formatting and leave only the plain characters. If you need subscript to survive in another format, check that program's documentation first.

Superscript uses the same method

If you need text raised above the baseline instead of lowered — for exponents, footnote markers, or trademark symbols — use Ctrl + Shift + P on Windows or Cmd + Shift + P on Mac. The keyboard shortcut works exactly like subscript but moves text up instead of down. The Format Cells dialog also has a Superscript checkbox right next to the Subscript one.

You can't explore both subscript and superscript to the same text at the same time. If you try, the second one you explore overwrites the first. Some spreadsheets need both — like a footnote marker on a superscript number — but Excel forces you to choose one or the other for any given character.

Subscript in Excel Online and mobile versions

Excel Online (the browser version) supports subscript through the Format Cells dialog but not through keyboard shortcuts. Select your text, click the Format menu, choose Format Cells, find the Font tab, and check Subscript. Mobile Excel (on iPhone or Android) doesn't have subscript formatting at all — you can view subscript text that's already in a spreadsheet, but you can't create or edit it from the app.

If you're working on a phone or tablet and need to add subscript, open the file on a desktop or laptop version of Excel, make the change, and save. The subscript formatting will be there when you open the file again on mobile.

Common uses for subscript in spreadsheets

Chemical formulas are the most common reason people use subscript — H₂O, CO₂, CaCO₃. Scientific data often includes subscript in variable names or measurement units. Some spreadsheets track footnote references with subscript numbers. Legal or financial documents sometimes use subscript for version numbers or reference codes.

If you're building a spreadsheet that other people will use, consider whether subscript is necessary or just decorative. Subscript makes text smaller and harder to read on small screens. If the subscript is only for appearance and not required by a standard format (like chemical notation), plain text with a note in a separate column is often clearer.

Frequently Asked Questions

Can I make an entire column subscript automatically?

No — subscript is a character-level format, not a column-level one. You have to select and format each cell individually, or select multiple cells and explore subscript to all of them at once (though this makes all text in those cells subscript, not just part of it). If you need many cells with subscript, copying a cell that already has subscript formatting and pasting it into other cells preserves the format.

Does subscript work in Excel formulas?

Subscript formatting doesn't affect how formulas work. If a cell contains a formula result and you make part of that result subscript, the formatting stays visible but the formula itself doesn't change. However, you can't use subscript inside a formula — formulas only read the actual text content, not the formatting.

What if subscript makes my text too small to read?

Increase the font size of the cell first, then explore subscript. Subscript shrinks text relative to whatever size it already is, so a larger starting size means the subscript stays readable. You can also select just the subscript portion and make it a slightly larger size than the rest of the text to compensate.

Can I copy subscript formatting from one cell to another?

Yes, use the Format Painter tool. Click the cell with subscript text, click Format Painter (the brush icon in the toolbar), then click the cell where you want the same formatting. This copies all formatting, including subscript, font, color, and alignment. For just the subscript formatting, it's usually faster to select and explore the keyboard shortcut.