Math Symbols

Fourth Root ∜

U+221C Added in Unicode 1.1 (1993)

The fourth root symbol (∜) marks the value that, multiplied by itself four times, equals the number under the radical.

Alt code Alt+8732
Codes
Unicode
Unicode name
Decimal
Windows Alt code
HTML entity
HTML decimal
HTML hex
Encodings & code escapes +
UTF-8 (hex bytes)
UTF-16 (hex units)
UTF-32
URL encoded
CSS content
JavaScript / TypeScript
JSON, Java, C#, C/C++
Python
Go
Rust, Swift, PHP, Ruby
Perl

Click any value to copy it. All escapes refer to the same code point U+221C.

How to type ∜ on Windows

The fastest method on a full-size keyboard is the Alt code Alt+8732.

  1. Make sure Num Lock is on.
  2. Hold down the Alt key.
  3. Type 8732 on the numeric keypad (the number row will not work).
  4. Release Alt. The fourth root symbol ∜ appears.

Note: Alt+8732 is a Unicode decimal code, not a classic code-page Alt code. It works in Microsoft Word, WordPad and some other apps, but not in Notepad or most browsers. In those apps, copy the symbol from this page instead.

No numeric keypad?

Press Win+. to open the emoji panel, choose the Symbols tab (Ω) and search for "fourth root". Or open Character Map from the Start menu, find ∜, click Select, then Copy.

How to type ∜ on a Mac

There is no direct keyboard shortcut for ∜ on a Mac.

For any symbol, the Character Viewer works: press Control+⌘+Space, type "fourth root" in the search box and double-click the result. It will be remembered under Frequently Used.

How to type ∜ on iPhone and iPad

The iOS keyboard does not include ∜, so the reliable way is to copy it from this page, then press and hold in any text field and tap Paste.

If you use it often, create a shortcut: open Settings → General → Keyboard → Text Replacement, paste ∜ in the Phrase field and type a short code such as ;fourth in the Shortcut field. Typing that code will then insert ∜ anywhere.

How to type ∜ on Android

Copy the symbol from this page, then long-press in a text field and choose Paste. Gboard also keeps a clipboard history: tap the clipboard icon on the toolbar to paste it again later.

For a permanent shortcut, open Gboard settings → Dictionary → Personal dictionary, add ∜ as the word and a short code as the shortcut.

How to type ∜ in Microsoft Word

  1. Type the Unicode hex code 221C where you want the symbol.
  2. Press Alt+X. Word converts the code into ∜.

This works on Windows in Word, Outlook and OneNote and needs no numeric keypad. You can also go to Insert → Symbol → More Symbols, set the font to a Unicode font and type 221C in the Character code box. In Excel, the formula =UNICHAR(8732) returns the symbol.

How to type ∜ in Google Docs

Open Insert → Special characters, then either search for "fourth root" or draw the symbol in the sketch box. Click the result to insert it. In Google Sheets, use =CHAR(8732).

∜ in HTML, CSS and code

FormatCode
HTML entity∜
HTML decimal∜
HTML hex∜
CSS content"\221C"
JavaScript"\u221C"
Python"\u221C"
URL encoded%E2%88%9C

Because ∜ is a standard Unicode character (U+221C), you can also paste it directly into any UTF-8 file. The escaped forms above are only needed when the file encoding is uncertain or the symbol must be entered on a keyboard without it.

Where the fourth root symbol is used

Used in math and physics for expressions like ∜16 = 2, where 2⁴ = 16. It appears in algebra textbooks and engineering calculations involving fourth-power relationships, such as quartic equations or radiation intensity formulas. It's sometimes confused with the square root symbol (√) or cube root symbol (∛), which look similar but have different small numbers or none at all above the checkmark.

Frequently asked questions

What does the fourth root symbol mean? +

It represents the number that, when raised to the fourth power, gives the value under the radical sign. For example, ∜81 = 3, since 3⁴ = 81.

Is there a difference between ∜x and x^(1/4)? +

No, they mean the same thing mathematically. ∜x is just the radical notation for the exponent expression x raised to the one-fourth power.

What is the Alt code for the fourth root symbol? +

The Alt code for ∜ is Alt+8732. Hold Alt, type 8732 on the numeric keypad, then release Alt. This is a Unicode code, so it works in Word and WordPad but not in every app; in other apps paste the symbol instead.

How do I type ∜ on a Mac? +

There is no dedicated Mac shortcut for ∜. Open the Character Viewer with Control + Command + Space, search for "fourth root", and double-click it. Or copy it from this page.

How do I type the fourth root symbol on iPhone or Android? +

Phone keyboards do not include ∜ by default. Copy it from this page and paste it, or add it as a text replacement shortcut in Settings so you can type it with a short abbreviation.

What is the HTML code for ∜? +

Use ∜ in HTML. In CSS use content: "\221C" and in JavaScript use "\u221C".

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