SymbolHub

Cube Root Symbol (∛)

The cube root symbol ∛ is Unicode U+221B, the radical sign with an index of 3. Press Copy to put it on your clipboard.

Unicode
U+221B
HTML
∛
Word
221B Alt+X

How to type the cube root symbol (∛)

The quickest way is to press Copy above and paste. To type ∛ yourself, use the method for your device below.

Windows

  1. In Word or Outlook, type 221B and press Alt + X. Alt + X converts the hex code before the cursor into the character, and back again.
  2. Press Win + R, type charmap and press Enter. Tick “Advanced view”, search for Cube Root, then Select and Copy. Character Map is built into every version of Windows.

Mac

  1. Press Control + Command + Space to open the Character Viewer, search for cube root and double-click it.
  2. With the Unicode Hex Input keyboard enabled (System Settings → Keyboard → Input Sources), hold Option and type 221B.

Linux & ChromeOS

  1. Press Ctrl + Shift + U, type 221b, then press Enter or Space. Works in GTK and IBus apps (GNOME, Firefox, Chrome, LibreOffice) and on ChromeOS.

iPhone & iPad

  1. Copy ∛ from this page, then go to Settings → General → Keyboard → Text Replacement and add it with a shortcut such as ;cube. The shortcut then turns into the symbol as you type, in every app.

Android

  1. Copy ∛ here, then open Gboard settings → Dictionary → Personal dictionary and add it with a shortcut.

Microsoft Word

  1. Type 221B, then press Alt + X.
  2. Insert → Symbol → More Symbols. Set “from” to Unicode (hex), type 221B in “Character code” and click Insert.

Google Docs

  1. Insert → Special characters, then search for “cube root” or draw it in the box.

Excel & Google Sheets

  1. Enter =UNICHAR(8731) in a cell. It works in Excel 2013 and later and in Google Sheets.

HTML

  1. Write ∛ or ∛ in your HTML.

What does ∛ mean?

∛ asks which number, multiplied by itself three times, gives the value inside: ∛27 = 3 and ∛−8 = −2. Unlike square roots, cube roots of negative numbers are ordinary real numbers. The character bakes the small index 3 into the radical, which is handy in plain text; in typeset maths the index is usually drawn separately.

Common uses

  • Volumes: side = ∛V for a cube
  • Plain-text formulas where a raised index is not available

Cube Root Symbol codes for HTML, CSS and programming

Every code below produces ∛. Use the HTML entity in web pages, the CSS escape in content, and the escape sequence in source code.

Unicode code pointU+221B
HTML decimal∛
HTML hex∛
CSS contentcontent: "\221B";
JavaScript"\u221B"
Python"\u221B"
Python (by name)"\N{CUBE ROOT}"
Java / C#"\u221B"
UTF-8 bytesE2 88 9B
UTF-16221B
URL encoded%E2%88%9B

∛ vs look-alike characters

These characters look similar to ∛ but have a different meaning and code. Pasting the wrong one can break search, sorting and screen readers.

CharNameWhen to use it
Square Root
U+221A		Square root, the radical without an index.
Fourth Root
U+221C		Fourth root.

Symbols similar to ∛

Click to copy, or open a symbol for its codes. See the full math symbols collection.

∛ character properties

Official Unicode name
CUBE ROOT
Also known as
cube root sign, third root
Code point
U+221B
Unicode block
Mathematical Operators (U+2200–U+22FF)
General category
Math symbol (Sm)
Added in
Unicode 1.1 (1993)
Plane
Basic Multilingual Plane (0)
Emoji
No, it is a text symbol

Frequently asked questions

How do I calculate a cube root in Excel?

Raise to the power one third: =A1^(1/3). For negative numbers use =SIGN(A1)*ABS(A1)^(1/3), because Excel returns an error for a negative base with a fractional power.

Is there an alt code for the cube root symbol?

No. ∛ is outside the Windows-1252 and code page 437 character sets, so no Alt + number code produces it. Copy it from this page, type 221B then Alt + X in Word, or find it in Character Map.

How do I type the cube root symbol on a Mac?

There is no single Option shortcut for ∛ on the US layout. Press Control + Command + Space to open the Character Viewer, search for “cube root” and double-click it, or copy it from this page.

What is the HTML code for the cube root symbol?

∛ has no named HTML entity. Use the numeric reference ∛ or ∛, or paste the character directly into a UTF-8 page.

What is the Unicode for the cube root symbol?

∛ is U+221B, officially named CUBE ROOT, in the Mathematical Operators block. It has been part of Unicode since version 1.1 (1993).