Windows Guide
How to Type the Square Root Symbol on a Windows Keyboard
Copy the square root symbol instantly
Method 1: Alt + 251 (Numeric Keypad)
- Make sure NumLock is on
- Hold Alt
- Type 251 on the numeric keypad (not the top row)
- Release Alt — √ appears
Works in: Notepad, Microsoft Office, most desktop apps.
Does not work in: browser address bars, laptops without a numeric keypad.
Why 251?
The Alt code system uses IBM Code Page 437 — the original IBM PC encoding from 1981. Position 251 was assigned to √. Windows preserved this mapping for backward compatibility.
Method 2: Type 221A then Alt+X (Word Only)
- Place cursor where you want √
- Type 221A
- Press Alt+X — Word converts it to √
Works without a numeric keypad. Word only — does not work in other apps.
Method 3: Windows Character Map
Press Win+S → search Character Map → find √ under Mathematical Operators → Select → Copy → Paste.
Which Method to Use?
| Situation | Best method |
|---|---|
| Desktop with numpad | Alt+251 |
| In Word, no numpad | 221A + Alt+X |
| Rare use, any app | Character Map |
Frequently Asked Questions
Does Alt+251 work on a laptop?
Only if your laptop has a dedicated numeric keypad. Most laptops don’t. Use Alt+X in Word or copy-paste instead.
Why doesn’t Alt+251 work in my browser?
Browsers intercept Alt key combinations for their own shortcuts. Use copy-paste when typing in browser fields.
Is √ the same character as a checkmark?
No. The square root symbol (√ U+221A) and a checkmark (✓ U+2713) are different Unicode characters that look similar at small sizes.