Mathematics

Sample Standard Deviation

Estimate population spread from a sample.

Let’s calculate.

Popularity

No account needed. Your inputs stay in this browser.

THE IDEA, SIMPLY

How it works

Estimate population spread from a sample.

FORMULA

s = √(Σ(x − mean)² / (n − 1))

A worked example

For 2, 4 and 6: sample deviation is 2.

Formula & detailed explanation

At least two values; divide by n−1.

Calculations use decimal arithmetic with 40 significant digits internally. Choose 0–8 decimal places for the displayed result. Trailing zeros are omitted. Rounding affects only the displayed and copied result; very small values may round to zero. Accepted inputs have up to 100 characters and magnitudes from 10⁻¹⁰⁰ to 10¹⁰⁰, plus zero.