Standard Deviation Calculator

Paste a list of numbers to get the standard deviation, with every step shown.

Separate with commas, spaces or new lines.
Decimals and negative numbers work.
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Standard Deviation
Mean
Count
Sum of squared deviations
Variance
Both versions
Coefficient of variation
Squared deviations
Work

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How to Calculate Standard Deviation and Variance

Mean x̄ = Σx ÷ n
Sample variance s² = Σ(x − x̄)² ÷ (n − 1)   Population variance σ² = Σ(x − μ)² ÷ n
Standard deviation = √variance

Worked Example

Tips

Use the sample version (n − 1, Bessel’s correction) when your data is a sample from a bigger group, which is most of the time; use the population version only when you have every member. Matches Excel’s STDEV.S / STDEV.P and VAR.S / VAR.P.