σ

Sigma Symbol (σ)

Copy the Sigma symbol σ to your clipboard, and see its Unicode code point, HTML entity, LaTeX command and how to type it on any device.

What does σ mean?

Lowercase sigma is the standard deviation in statistics (a measure of spread), mechanical stress in engineering, electrical conductivity, and surface charge density in physics. Its capital form Σ is the summation operator. σ is the lowercase form of Sigma, letter 18 of 24 in the Greek alphabet (pronounced SIG-ma). Its capital counterpart is Σ. In science and maths it is used for: Summation (Σ), standard deviation and stress (σ).

Codes and properties

Characterσ
Unicode nameGREEK SMALL LETTER SIGMA
Code pointU+03C3
Decimal963
Unicode blockGreek and Coptic
HTML entityσ · σ · σ
CSS\03C3
JavaScript / JSON\u03C3
Python\u03C3 or \N{GREEK SMALL LETTER SIGMA}
UTF-8 bytesCF 83
LaTeX\sigma

How to type σ

  • Copy & paste: press the Copy button above, then paste σ anywhere — Word, Google Docs, email, chat or code.
  • Windows (Word, WordPad, Outlook): type 03C3 then press Alt+X. In any app, Win+. opens the symbol panel.
  • Windows Alt code: hold Alt and type 229 on the numeric keypad (Num Lock on), then release Alt. Works in Word, Notepad and most desktop apps.
  • Mac (any symbol): switch to the Unicode Hex Input keyboard, hold Option and type 03C3; or press Ctrl+Cmd+Space and search “greek small letter sigma”.
  • Linux (GTK/IBus): press Ctrl+Shift+U, type 03c3, then Space.
  • HTML: σ renders as σ.
  • LaTeX: \sigma in math mode (amssymb package for some symbols).

Frequently asked questions

What does σ mean in statistics?

Standard deviation — how far values typically fall from the mean. About 68% of a normal distribution lies within ±1σ.

How is σ different from Σ?

Lowercase σ is standard deviation (or stress); capital Σ means ‘sum of’.

How do I type σ on Windows?

In Microsoft Word type 03C3 and press Alt+X. In any app press Win+. to open the symbol panel, or copy σ from this page. You can also hold Alt and type 229 on the numeric keypad.

How do I type σ on a Mac?

Open the Character Viewer with Ctrl+Cmd+Space and search “greek small letter sigma”, or switch to Unicode Hex Input and hold Option while typing 03C3.

What is the HTML code for σ?

Use σ or σ (hex) or σ (decimal).

What is the LaTeX command for σ?

Use \sigma in math mode.

Related symbols

ΣCapital SigmaτTauρRhoυUpsilonπPiφPhiοOmicronχChiξXi

Keep exploring

Reference: Unicode code chart: Greek and Coptic (U+0370–U+03FF)