Standard Deviation Calculator

How the calculation works

The mean is x̄ = Σx/n. Population variance is Σ(x − x̄)²/n; sample variance is Σ(x − x̄)²/(n − 1). Standard deviation is the square root of variance.

Inputs

• Observations: Separate numbers with spaces or semicolons. Use a dot or comma as the decimal separator; up to 1,000 numbers.
• Data type

Calculation details

Sample statistics require at least two values. Select population when your data includes every member of the group, or sample when estimating from a subset.

For 2; 4; 4; 4; 5; 5; 7; 9, the mean is 5, population variance is 4, and standard deviation is 2. Deviation uses the original units; variance uses squared units.