Sample vs population
Use population standard deviation when the dataset contains every value in the group you care about. Use sample standard deviation when the dataset is a sample used to estimate a wider population.
Formula
Population variance divides squared deviations by n. Sample variance divides by n - 1. Standard deviation is the square root of variance.
References
- Khan Academy: Sample and population standard deviation, accessed 2026-05-13.
- Calculator.net Standard Deviation Calculator - competitor benchmark, accessed 2026-05-13.
Last reviewed: 2026-05-13