Standard Deviation Calculator

Population and sample standard deviation with variance.

Result

Mean5
Variance4.5714
Std deviation2.1381

Standard Deviation Calculator — FAQs

Sample vs population SD?

Sample divides by n−1 (Bessel's correction) — the right choice for a sample of a larger group. Population divides by n.

What does standard deviation tell you?

How spread out values are around the mean — ~68% of data falls within 1σ, ~95% within 2σ for normal distributions.

Population vs sample SD?

Population divides by n; sample divides by n−1 (Bessel's correction) — use sample when estimating from a subset.

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