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Standard Deviation Symbol (Sigma) (σ)
The standard deviation symbol is the Greek lowercase sigma (σ) — it measures how spread out a set of numbers is around its mean.
Standard Deviation Symbol (Sigma) codes
| Code | Value |
|---|---|
| Unicode code point | U+03C3 |
| Unicode name | Greek Small Letter Sigma |
| HTML named entity | σ |
| HTML decimal | σ |
| HTML hex | σ |
| CSS content code | \3C3 |
| JavaScript / JSON | \u03C3 |
| Windows Alt code | No standard Alt code — copy it from the card above |
| LaTeX | \sigma |
Standard Deviation Symbol (Sigma) variants (4)
4 related glyphs — click any tile to copy it. Tiles with a page open that symbol's own page.
Meaning & usage
In statistics, σ is the standard deviation of a whole population: a small σ means values huddle close to the average, a large σ means they are scattered. Exam scores, heights, manufacturing tolerances and investment risk are all described with it.
When the data is only a sample, textbooks switch to the letter s instead — that is why 'sample standard deviation symbol' searches exist for both. The capital Σ is a different job entirely: summation.
Examples in use
- Heights: mean 170 cm, σ = 7 cm
- A σ of 0 would mean every value is identical
- Exam results: μ = 72, σ = 9
How to type the standard deviation symbol (sigma)
Windows
There is no Alt code or direct key for σ. In Microsoft Word, type 03C3 and press Alt+X to convert it. Everywhere else, click the Copy button at the top of this page and paste it (Ctrl+V) — that always works.
Mac
There is no Option-key shortcut for σ on a Mac. Open the Character Viewer with Control+Command+Space, search for "Standard Deviation Symbol (Sigma)", and double-click to insert — or copy it from this page.
iPhone & Android
Most phone keyboards have no built-in key for σ. Open this page on your phone, tap Copy, then paste it into your message or bio. (On Android, Gboard's emoji search finds some symbols by name.)
Linux
Press Ctrl+Shift+U, type 03c3 and press Enter (works in most GTK apps and terminals with IBus). Or copy it from this page.
Frequently asked questions
Is the standard deviation symbol σ or s?
Use σ (sigma) for the standard deviation of an entire population, and s for the standard deviation of a sample. Most calculators and Excel's STDEV.P vs STDEV.S follow the same split.
What is a 'good' standard deviation?
There is no universal good value — it depends on the data. What matters is σ compared with the mean: σ much smaller than the mean means tight, consistent data.
How do I type σ in Word or Excel?
Copy σ from this page, or in Word type 03C3 then Alt+X. In Excel, Insert → Symbol → Greek and Coptic → σ.
Why does σ sometimes show as a box or question mark?
The box (called tofu) means the device or font viewing it has no drawing for U+03C3 (Greek Small Letter Sigma). The character itself is fine — try a different font or a newer device, or use one of the variants on this page.
Is the Standard Deviation Symbol (Sigma) free to use?
Yes. σ is a standard Unicode text character published in the Unicode Character Database. You may use it in personal and commercial documents, designs and products without permission or payment.
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Data: Unicode Character Database · Page updated 2026-11-13