How to type the square root symbol
Use the shortcut for the device or app you have open, or copy the symbol above.
- Windows (numeric keypad)
- Hold Alt and type 251 on the numeric keypad, then release Alt
- Windows (Word)
- Type 221A then press Alt + X, or in an equation type \sqrt and a space
- Mac
- Option + V on a US keyboard layout
- iPhone / iPad
- Copy √ from this page, or add a Text Replacement in Settings → General → Keyboard
- Android
- Open the keyboard symbol pages (?123, then =\<) to look for √, or copy it from this page
- Google Docs
- Insert → Special characters and search for square root, or use Insert → Equation
- Microsoft Word
- Type 221A then Alt + X, Option + V on Mac, or Insert → Symbol
What is the square root symbol?
The square root symbol √ is Unicode U+221A SQUARE ROOT, also called the radical sign. It marks the square root of a number, so √9 reads as the square root of 9.
How to type the square root symbol and use it
On Windows with a numeric keypad, hold Alt and type 251 to get √. That code comes from the legacy DOS character set, so if another character shows up in a particular app, use the Word hex method (type 221A, then Alt + X) or the copy button. On a Mac, press Option + V. Google Docs offers Insert → Special characters, and both Word and Docs equation editors turn \sqrt followed by a space into a radical.
The character √ is a single glyph, with no bar over the number. In plain text, group the radicand with parentheses so the meaning is clear: √(x + 1) is different from √x + 1. In Word and Docs equations, the radical template draws the full bar over the expression for you.
On the web, write √ or √ in HTML, or paste √ into a UTF-8 file. In CSS content, use the escape \221A. UTF-8 encodes it as the three bytes E2 88 9A. In spreadsheets, use the SQRT function for calculations, since the pasted symbol is text rather than an operator.
Other roots have their own characters. ∛ (U+221B) is the cube root and ∜ (U+221C) is the fourth root, both in the related characters row. For higher roots, write the index as a superscript digit before the radical sign, or use an equation editor. Powers and exponents are covered by the Superscript Generator.
Typical uses include math homework, formulas in notes, geometry (the length of a diagonal is √(a² + b²)), and statistics. Pasting √ into email, chat, or a PDF keeps the formula searchable as text instead of an image.
Frequently asked questions
What is the Alt code for the square root symbol?
On Windows with a numeric keypad, hold Alt and type 251 to get √. In Word, you can also type 221A and press Alt + X.
How do I type √ on a Mac?
Press Option + V on a US keyboard layout.
What is the HTML code for the square root symbol?
Use √ or √ in HTML. In CSS, the escape is \221A.
How do I write a square root in Excel?
Use the SQRT function, such as =SQRT(16). Paste √ only when you want the symbol as text.
How do I type a cube root symbol?
Copy ∛ (U+221B) from the related characters row above. The fourth root ∜ (U+221C) is there too.
Is the square root symbol free to use?
Yes. It is a standard Unicode character, free to copy and paste with no account required.