Standard Deviation Calculator

Calculate mean, variance, and both population and sample standard deviation from any list of numbers — separated by commas, spaces, or new lines.

Inputs

Results

Count
6
Mean (average)
18
Variance (population)
151.666667
Population standard deviation (σ)
12.315302
Sample standard deviation (s)
13.490738
Sum · Min · Max
108 · 4 · 42

About the Standard Deviation Calculator

Standard deviation measures how spread out a set of numbers is around the mean. A small standard deviation means values cluster close to the average; a large one means they're widely scattered.

Use the population formula (σ) when your data represents the entire population, and the sample formula (s) when your data is a sample drawn from a larger population — the sample formula divides by n−1 to correct for bias.

Frequently asked questions

Population SD divides by n. Sample SD divides by n−1 (Bessel's correction) to provide an unbiased estimate of the true population SD from a finite sample.

More math calculators

Browse other categories