Variance Calculator
Calculate population and sample variance with the divisor shown.
What is Variance?
Variance is the average squared distance from the mean: σ² divides the squared deviations by n, while s² divides by n − 1. The second form corrects for the fact that a sample spreads out less than the population it came from, and choosing between them is the single most common mistake in the whole topic.
How it works
Both figures are computed in one pass and the page names which divisor is in play in the substituted working line, with a switch that changes the headline rather than hiding the other answer. The squared units are why the square root has its own page: a variance of 54.1 cannot be compared with a mean of 23.1 until it is back in the original units.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
Nothing is uploaded — every tool in this category runs entirely in your browser.