Standard Deviation Calculator

Population vs. sample standard deviation

Standard deviation measures how spread out a set of numbers is around the mean. The population standard deviation (σ) is used when your data represents the entire population — it divides by n. The sample standard deviation (s)is used when your data is a sample drawn from a larger population — it divides by n−1 (Bessel's correction) to give an unbiased estimate of the true population variance. Both are shown alongside variance (the squared standard deviation), mean, median, min, max, and range. Paste numbers in any common format; all computation runs locally in your browser.