How do I calculate standard deviation? Enter your numbers above and the result updates instantly. For example: Numbers: 10, 12, 23, 23, 16, 23, 21, 16 → Sample std deviation: 5.2372.
Is this Standard Deviation Calculator free? Yes — completely free with no sign-up or paywall. It runs entirely in your browser and keeps working offline; the numbers you enter never leave your device.
How accurate is it? It uses the standard published formula for standard deviation. Results are estimates for planning — not financial, tax, medical, engineering, or legal advice.