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📊 Variance Calculator

Enter up to eight numbers to calculate the variance and standard deviation, for either a full population or a sample.

What This Calculator Does

Variance measures how spread out a set of numbers is from their average (mean). A larger variance means the values are more spread out; a smaller variance means they cluster close to the mean. Leave any of the optional value fields blank to exclude them.

The Formula

Variance is the average of the squared differences from the mean. For a population, divide the sum of squared differences by the total count (N). For a sample, divide by one less than the count (n – 1), known as Bessel’s correction, which gives a less biased estimate when working with a subset of a larger population.

Standard Deviation

Standard deviation is simply the square root of variance, expressed in the same units as your original data, which often makes it easier to interpret than variance alone.

Note: This tool is intended for general educational and planning purposes.

Last reviewed August 2026