The short answer: on a Mac, press Option + V. On Windows (in Word), type 221A then Alt + X. On a Chromebook or Linux, press Ctrl + Shift + U, type 221a, then Enter. Or just copy it below.
Tap a symbol to copy it
The radical sign √ sits above the basic Alt-code range, so the routes differ a little by platform. If you need the bar over the number (a proper radical), that’s a separate job for the equation editor — covered below.
Quick reference
| Platform | How |
|---|---|
| Mac | Option + V |
| Windows (Word) | Type 221A, then Alt + X |
| Chromebook / Linux | Ctrl + Shift + U, type 221a, then Enter |
| Excel | =UNICHAR(8730) or Insert → Symbol → 221A |
| Google Docs | Insert → Special characters → search “square root” |
| HTML | √ or √ |
| LaTeX / Markdown | \sqrt{x} |
| Unicode | U+221A |
Windows
In Word, type 221A then press Alt + X. Word converts the hex code into √.
If you’re not in Word (Notepad, a browser field, etc.), the Alt + X trick won’t work. Use one of these instead:
- Copy √ from the box above.
- Character Map: open the Character Map app, find √, and copy it.
- Legacy numpad code: on a full keyboard, hold Alt and type 251 on the numeric keypad. This works in many older programs but is inconsistent — it depends on the app’s code page.
Why is there no Alt + 0251 code? Codes like Alt + 0NNN use the ANSI (Windows-1252) set, which doesn’t include √. The legacy Alt + 251 (no leading zero) uses the older OEM code page, where √ does exist — which is why one works and the other doesn’t.
Mac
Press Option + V. That’s the whole thing.
(This is for the standard U.S. keyboard layout. On some other layouts the key differs — if Option + V gives you something else, just copy √ above.)
Chromebook & Linux
Both use the same Unicode-input trick:
- Click into a text field.
- Press Ctrl + Shift + U — you’ll see an underlined u.
- Type 221a.
- Press Enter or Space.
This works in most text fields but not everywhere (some apps block it), so keep copy-paste as a backup.
Excel
Excel doesn’t support Alt + X. Instead:
- Type
=UNICHAR(8730)in a cell (8730 is the decimal version of U+221A). - Or go to Insert → Symbol, set the character code to 221A, and insert.
- Or simply copy √ and paste it.
(Note: =SQRT(16) calculates a square root — it gives you 4. That’s different from displaying the √ symbol.)
Google Docs
- Just the character: Insert → Special characters, then search “square root” and click √.
- A proper radical (bar over the number): Insert → Equation, then use the square-root button or type
\sqrt.
The radical with a bar (over the number)
The plain √ character does not draw a line over what follows. Type √16 and you get exactly that — a √ sitting next to a 16, with no bar connecting them. A true radical draws the bar (the vinculum) across the whole radicand.
For that, use an equation:
- Word: press Alt + = to start an equation, then type
\sqrtand the value. The bar renders automatically. - Google Docs: Insert → Equation, then the square-root button or
\sqrt.
Cube roots and nth roots
- Cube root ∛ — type 221B then Alt + X in Word.
- Fourth root ∜ — 221C.
- Any nth root — the equation editor’s
\sqrtwith an index is cleanest (it lets you set the small number in the crook).
Phones (iPhone & Android) and HTML
- Phone: √ isn’t on the standard keyboard, so copy and paste is the reliable route. If you use it often, add a text-replacement/keyboard shortcut (e.g. type
sqrt→ √) in your keyboard settings so it’s always a tap away. - HTML: use
√or√. - LaTeX / Markdown math:
\sqrt{x}for a proper radical.
Examples
√16 = 4 · √2 ≈ 1.414 · the diagonal of a right triangle = √(a² + b²)
Troubleshooting
| Problem | Fix |
|---|---|
| No Alt + 0NNN code works | √ is above that range — use Word’s 221A → Alt + X, or copy it. |
| Alt + X does nothing | You’re not in Word. Use Character Map, copy-paste, or the numpad legacy code. |
| I need the line over the number | That’s the equation editor (\sqrt), not the plain √ character. |
| The symbol shows as a box (□) | Your font lacks √. Switch to a common font like Arial, Calibri, or Times New Roman. |
Frequently Asked Questions
How do I type the square root symbol?
On a Mac, press Option + V. On Windows, type 221A and then press Alt + X in Microsoft Word, or copy and paste the square root symbol (√).
How do I get the line over the number in a square root?
Use an equation editor rather than a plain symbol. In Microsoft Word, press Alt + = to open an equation, then type \sqrt followed by the value. In Google Docs, use Insert → Equation and create the square root expression there.
Is there an Alt code for the square root symbol?
There is no standard Alt + 0NNN code for the square root symbol (√). Instead, use 221A + Alt + X in Microsoft Word or copy and paste the symbol. Some older Windows applications may accept the legacy code Alt + 251.
How do I type the cube root symbol (∛)?
In Microsoft Word, type 221B and then press Alt + X. You can also copy and paste the cube root symbol (∛).
How do I type the square root symbol on a Chromebook?
Click into a text field, press Ctrl + Shift + U, type 221a, then press Enter or Space. If an app blocks Unicode input, copy √ and paste instead.
Why does the square root symbol show up as a box?
The box (□ or “tofu”) means your current font doesn’t include √. Switch to a common font such as Arial, Calibri, or Times New Roman, all of which contain the symbol.
Recap
Mac Option + V · Windows 221A → Alt + X in Word · Chromebook/Linux Ctrl + Shift + U → 221a → Enter. For a proper radical bar, use the equation editor.
Written by Igor R. Tested on Windows 11, macOS, and Microsoft 365. Last updated Jul-26. The square root sign is U+221A in the Unicode Standard.