SymbolHub

Sigma Symbol (Σ)

The sigma symbol Σ is Unicode U+03A3, the Greek capital letter that means “sum”. Press Copy to put it on your clipboard, or type it with Alt + 228 on Windows.

Unicode
U+03A3
HTML
Σ
Windows
Alt + 228

How to type the sigma symbol (Σ)

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

Windows

  1. Hold Alt and type 228 on the numeric keypad. This older code (from code page 437) works in Notepad, Word and most desktop apps.
  2. In Word or Outlook, type 03A3 and press Alt + X. Alt + X converts the hex code before the cursor into the character, and back again.
  3. Press Win + R, type charmap and press Enter. Tick “Advanced view”, search for Greek Capital Letter Sigma, 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 sigma and double-click it.
  2. With the Unicode Hex Input keyboard enabled (System Settings → Keyboard → Input Sources), hold Option and type 03A3.

Linux & ChromeOS

  1. Press Ctrl + Shift + U, type 3a3, then press Enter or Space. Works in GTK and IBus apps (GNOME, Firefox, Chrome, LibreOffice) and on ChromeOS.

iPhone & iPad

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

Android

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

Microsoft Word

  1. Type 03A3, then press Alt + X.
  2. Insert → Symbol → More Symbols. Set “from” to Unicode (hex), type 03A3 in “Character code” and click Insert.

Google Docs

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

Excel & Google Sheets

  1. Enter =UNICHAR(931) in a cell. It works in Excel 2013 and later and in Google Sheets.

HTML

  1. Write Σ or Σ in your HTML.

What does Σ mean?

Sigma is the eighteenth letter of the Greek alphabet and has three forms. The capital Σ is the one most people want: in maths it means sum, so Σxᵢ adds up every value of x. The lowercase σ is the symbol for standard deviation, and the Greek language also has a final form ς, used only at the end of a word.

Σ also turns up well outside maths. “Six Sigma” is a quality-management method named after six standard deviations. Online, “sigma” became slang for a self-reliant lone wolf, and US fraternities such as ΣΧ and ΣΑΕ use the capital. On Windows, Alt + 228 types Σ and Alt + 229 types σ, both from the old IBM PC character set.

Common uses

  • Summation in formulas: Σᵢ₌₁ⁿ i = n(n + 1)/2
  • Statistics: σ = 2.5 for a standard deviation, σ² for variance
  • Business: Six Sigma process improvement
  • Greek words: σοφός, and final ς in λόγος

Sigma Symbol codes for HTML, CSS and programming

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

Unicode code pointU+03A3
HTML entity (named)Σ
HTML decimalΣ
HTML hexΣ
CSS contentcontent: "\3A3";
JavaScript"\u03A3"
Python"\u03A3"
Python (by name)"\N{GREEK CAPITAL LETTER SIGMA}"
Java / C#"\u03A3"
LaTeX\Sigma
UTF-8 bytesCE A3
UTF-1603A3
URL encoded%CE%A3
Alt code (CP437)Alt + 228

Σ vs look-alike characters

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

CharNameWhen to use it
N-Ary Summation
U+2211		N-ary summation (U+2211), the maths operator. It is larger and is what Option + W types on a Mac. Use ∑ for big-operator sums in equations, Σ in text.
Greek Sigma
U+03C3		Greek small sigma (U+03C3), the standard-deviation symbol.
Greek Final Sigma
U+03C2		Greek small final sigma (U+03C2), only used at the end of Greek words.
Capital Esh
U+01A9		Latin capital letter esh (U+01A9), a phonetic letter that looks like a Σ.

Symbols similar to Σ

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

Σ character properties

Official Unicode name
GREEK CAPITAL LETTER SIGMA
Also known as
sigma, capital sigma, greek letter sigma, sum symbol
Code point
U+03A3
Unicode block
Greek and Coptic (U+0370–U+03FF)
General category
Uppercase letter (Lu)
Added in
Unicode 1.1 (1993)
Plane
Basic Multilingual Plane (0)
Emoji
No, it is a text symbol

Frequently asked questions

What is the difference between Σ and ∑?

Σ (U+03A3) is the Greek capital letter sigma. ∑ (U+2211) is the n-ary summation operator designed for equations. They look alike; ∑ is usually bigger.

What is the alt code for sigma?

Hold Alt and type 228 for Σ or 229 for the lowercase σ on the numeric keypad.

What does σ mean in statistics?

σ is the standard deviation of a population, a measure of how spread out the values are. σ² is the variance.

What is the alt code for the sigma symbol?

On Windows, hold Alt and type 228 on the numeric keypad to get Σ. On a laptop without a keypad, copy it from this page or use 03A3 then Alt + X in Word.

How do I type the sigma symbol on a Mac?

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

What is the HTML code for the sigma symbol?

Use the named entity Σ or the numeric reference Σ (hex Σ). All three display Σ in every browser.

What is the Unicode for the sigma symbol?

Σ is U+03A3, officially named GREEK CAPITAL LETTER SIGMA, in the Greek and Coptic block. It has been part of Unicode since version 1.1 (1993).