Variance Calculator
Paste your numbers and get the sample or population standard deviation, variance, mean, SEM and CV% — with the squared deviations shown step by step.
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Result
About this tool
This page opens the standard deviation calculator focused on variance: paste your numbers, run it, and the variance card is highlighted among the results, next to the standard deviation, mean, standard error and coefficient of variation from the same input.
Variance is the average squared distance from the mean. Two passes compute it exactly: first x̄ = Σxᵢ ÷ n, then Σ(xᵢ − x̄)², divided by n − 1 for a sample or by n for a population. For 2, 4, 4, 4, 5, 5, 7, 9 the squared deviations sum to 32, so the population variance is 32 ÷ 8 = 4 and the sample variance is 32 ÷ 7 ≈ 4.5714.
Because squaring makes its unit the square of the data's unit (dollars², cm²), variance is mostly a stepping stone: its square root — the standard deviation — is the readable spread. The step table under the results shows every xᵢ − x̄ and its square, so you can trace exactly how the variance was built from your list.
Example. The values 2, 4, 4, 4, 5, 5, 7, and 9 have population standard deviation 2.
Limit. Sample mode divides by n−1, and the squared-deviation table shows at most 50 rows.