√ Square root Symbol — Copy and Paste, Alt Code

01 — Origin

Where the Square root symbol comes from

The radical sign is a stylised letter r, for the Latin radix, root. Christoff Rudolff introduced it in 1525; the horizontal bar over the expression came later, from Descartes, and it is what turns the mark from a vague indicator into an unambiguous statement of what is inside the root.

Maths at every level, plus the occasional aesthetic use in bios where it reads as a tick with extra character. In plain text it has a practical weakness: without the overbar there is nothing to show where the root ends.

Worth knowing

For cube and higher roots there are separate characters ∛ ∜, and beyond the fourth root there is no symbol at all — you write it as a fractional exponent instead.

02 — Codes

Square root symbol codes

Tap any value to copy it. All of them produce the same character — they just belong to different places.

03 — How to type

How to type √ on any keyboard

Keyboard, code, markup or document — the route to U+221A differs by tool.

Windows

Hold Alt and type 8730 on the numeric keypad, then release. Without a keypad, use the Character Map app (search “charmap”).

Mac

Press Control + Command + Space to open the character viewer, then search “square root”. Double-click to insert.

Phone

There is no shortcut on a phone keyboard. Tap the symbol at the top of this page, then long-press in any text field and choose Paste.

Web and code

In HTML write √ or √. In CSS content: "\221A". Make sure the page is served as UTF-8 and the raw character works too.

04 — Font support

Will √ actually show up?

We checked 147 fonts installed on a normal machine and counted how many of them contain this character. A symbol missing from a font is drawn as an empty box — the text is still correct, it just cannot be drawn.

89% 131 of 147 fonts

Safe in most places. Common fonts have it. Older or decorative fonts sometimes do not, so a fallback font will kick in.

05 — Similar

Symbols people confuse with √

Close enough to be mistaken for it, and still a different code point every time.

∞ InfinityU+221E · has its own page

06 — Related

Other mathematical symbols

Symbols from the same family, each with its own page: where it came from, how to type it and how well fonts support it.

∫ Integral symbolIn 89% of system fonts ≠ Not equal symbolIn 89% of system fonts ≈ Approximately equal symbolIn 89% of system fonts ≤ Less than or equal symbolIn 87% of system fonts ± Plus-minus symbolIn 97% of system fonts ÷ Division symbolIn 97% of system fonts

07 — Same block

Math symbols

Operators, set theory, logic, calculus — everything past the number row.

All math symbols →

08 — FAQ

Square root symbol — questions

How do I type the Square root symbol?

On Windows hold Alt and type 8730 on the numeric keypad. On Mac open the character viewer with Control + Command + Space and search “Square root”. Or just tap the symbol on this page — it goes straight to your clipboard.

What is the HTML code for √?

Write it as √ or √ in HTML, \221A in CSS content, and \u221A in JavaScript. All four produce the same character.

Is √ an emoji?

No. √ is a text character — it takes the colour of the text around it and works in usernames, filenames and documents. An emoji is replaced by a colour picture and is sometimes stripped by forms and systems.

Why does √ show as a box on some devices?

Because that font has no drawing for this character. We checked 147 fonts on a normal machine and 131 of them include it. The character itself is always correct; only the drawing is missing.

√Square root symbol