Variance Calculator
Compute the sample or population variance of a data set.
Results update as you type.
About this calculator
Variance is the average of the squared deviations from the mean and is the square of the standard deviation. This calculator gives the sample variance (sum of squared deviations divided by n − 1) or the population variance (divided by n), along with the standard deviation and mean. Variance is expressed in squared units, which is why the standard deviation — its square root — is usually easier to interpret.
Frequently asked questions
How is variance related to standard deviation?
The standard deviation is the square root of the variance. Variance is in squared units (for example, squared dollars), while the standard deviation is back in the original units, so the two always describe the same spread.
When do I use n versus n − 1?
Divide by n − 1 when your data is a sample used to estimate a larger population; divide by n when your data represents the whole population you care about.
Results are estimates for general guidance only, not financial, medical or tax advice.