Sigma Symbol (σ)

The sigma symbol σ is a Unicode text character rather than an image. Its code point is U+03C3, and Unicode identifies it as GREEK SMALL LETTER SIGMA. The character σ is the Greek small letter sigma. In mathematical and scientific documents it may be assigned a context-specific meaning, including use as a variable. Because it remains encoded text, it can be selected, copied, searched, indexed, and pasted into apps that support the character. The exact glyph can vary with the active font and platform, so the Unicode value is the reliable way to verify that the intended character was used.

Supporting searches such as “sigma symbol in mathematics”, “sigma greek symbol”, “sigma math symbol”, “sigma symbol math”, “symbol for sigma” generally describe related tasks: identifying the character, copying it, entering it on a keyboard, or understanding its documented use. This page keeps those small wording variations together instead of creating separate pages for the same symbol intent. Use the copy control for the fastest method, then consult the platform instructions for Word, Google Docs, Windows, macOS, iPhone, Android, and Chromebook.

The character-code section provides the Unicode value, HTML decimal and hexadecimal references, and a CSS escape. When the symbol conveys an action, category, hazard, legal status, or other important meaning, pair it with readable text rather than relying on the glyph alone. The formatting rules, examples, and common-mistake list below are based on the cited official references and are intended to help preserve the correct character across documents and websites.