Variance Calculator

About this calculator

This calculator computes both population variance (σ²) and sample variance (s²) from a list of numbers, along with their square roots, the population and sample standard deviations. Population variance divides the sum of squared deviations from the mean by N, while sample variance uses Bessel's correction — dividing by n−1 instead of n — to produce an unbiased estimate when the data is only a sample of a larger population.

Variance measures how spread out values are around the mean, and it's foundational to statistics: it feeds into confidence intervals, ANOVA, regression analysis, and risk metrics in finance, where the standard deviation of returns is used as a proxy for volatility.

Statistics students working through coursework, data analysts and researchers summarizing a dataset, quality control engineers measuring process consistency, and finance professionals assessing investment risk all reach for this calculation. Enter your data set as a list to get both variance types at once.