Variance Calculator
Free Variance Calculator: use =VAR.S(range) for a sample, or =VAR.P(range) for a full population.
n = 6 · mean = 14.67
Std deviation σ = 4.131
How it works
In Excel or Google Sheets, use =VAR.S(range) for a sample, or =VAR.P(range) for a full population.
List your numbers in one column or row.
In a blank cell type =VAR.S( and select the range.
Press Enter for the sample variance.
Use =VAR.P(range) when the data is the whole population rather than a sample.
What this does
Variance is the average squared distance of each value from the mean — the raw measure of spread that standard deviation is built on. Because it squares the differences, its units are squared too (euros², points²), which is why standard deviation, its square root, is usually the figure people quote. Variance still matters wherever the maths needs the un-rooted quantity, such as combining the spread of independent sources.
A worked example
For 12, 15, 9, 21, 17, 14 (mean 14.67), =VAR.S(A1:A6) returns about 17.07. Take its square root and you get the standard deviation, ≈4.13. The tool above shows both so you can see the relationship: variance is the engine, standard deviation is the readable dashboard. Variance underpins portfolio theory, ANOVA, and any model that has to add up uncertainty from several sources. When the next step is more maths rather than a human-readable report, variance is the quantity you keep.
Common mistakes
- Reporting variance where readers expect standard deviation — the squared units mislead.
- Choosing VAR.P for a sample, which understates the true spread.
- Including non-numeric cells in the range.
- Forgetting that adding a constant to every value leaves variance unchanged, while scaling multiplies it by the square.
FAQ
Variance or standard deviation?
Report standard deviation to humans (same units as the data); keep variance for further calculation, where its additive property across independent sources is convenient.
Why square the differences?
Squaring removes the sign so positive and negative deviations do not cancel, and it penalises large deviations more, which is exactly what a spread measure should do.
Does Google Sheets have VAR.S?
Yes — VAR.S and VAR.P work identically in Google Sheets, so these formulas transfer with no change.
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