Math & Statistics Tools
Standard Deviation & Variance Calculator
Calculate population and sample standard deviation and variance with distribution analysis.
Loading tool…
What is Std Dev?
Standard deviation measures data spread around the mean. Population uses n; sample uses n-1 (Bessel correction).
How it works
We compute mean, then variance = sum of squared deviations / n (population) or n-1 (sample), then sd = sqrt(variance).
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.