Standard Deviation Calculator

Calculate standard deviation, variance, mean, median, and other statistics for a data set. Supports population and sample calculations.

Population vs Sample

Result

Fill in the fields above, then press Calculate.

A standard deviation calculator computes the spread of a data set by calculating sample or population standard deviation, variance, mean, and other descriptive statistics with a step-by-step breakdown.

Enter your data as a list of numbers separated by commas, spaces, or new lines. Select whether your data is a Population (entire group) or a Sample (subset). Click Calculate to see the standard deviation, variance, mean, and a step-by-step breakdown of the calculation.

Examples

Test Scores

For scores 10, 12, 23, 23, 16, 23, 21, 16, the sample standard deviation is 5.24.

Frequently Asked Questions

What is the difference between population and sample standard deviation?
Sample standard deviation uses n-1 in the denominator (Bessel's correction) to provide an unbiased estimate for the wider population, whereas population standard deviation uses N.
Related Calculators
Mean, Median, Mode Calculator
Statistics Calculator
Z-Score Calculator
Confidence Interval Calculator

Quick Tips

  • •Use sample standard deviation (n-1) when your data is a subset of a larger population.
  • •Double-check your inputs — a single outlier can dramatically change the standard deviation.
  • •Use the step-by-step breakdown to verify intermediate calculations.