Standard Deviation Calculator
Calculate population and sample standard deviation, variance, mean, and more from a data set.
8 values entered
Statistics
How to Use the Std Deviation Calculator
Enter your data as comma-separated numbers (e.g. "2, 4, 4, 5, 9"). The calculator instantly computes population and sample standard deviation, mean, median, and more.
Formula
Population σ: √[ Σ(xᵢ − μ)² / N ]
Sample s: √[ Σ(xᵢ − x̄)² / (N−1) ]
Frequently Asked Questions
Population vs sample standard deviation?
Use population SD when you have complete data. Use sample SD when your data is a subset of a larger population — dividing by N−1 (Bessel's correction) gives an unbiased estimate.
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