Standard Deviation Calculator
Calculate population and sample standard deviation, variance, mean, and other statistics.
About Standard Deviation
Standard deviation measures how spread out values are around the mean. Population SD (σ): divide by N. Sample SD (s): divide by (N-1) — used when data is a sample of a larger population (Bessel's correction). Lower SD means data is clustered close to mean; higher SD means more dispersion.
Enter Data
Numbers (comma or space separated)
Results
Sample SD (s)
5.24
Population SD (σ)
4.90
Sample Variance
27.43
Population Variance
24.00
Mean (μ)
18
Count (n)
8