Variance Calculator
Calculate population variance, sample variance and sample standard deviation from a browser-local number list.
What would you like to do next?
Compare the two common variance denominators
Enter at least two numeric values and the calculator finds their mean-centered squared deviations. It reports population variance using n, sample variance using n minus one and the corresponding sample standard deviation. Placing the two variance definitions together makes the denominator choice explicit instead of letting a software default quietly determine the answer.
Match the definition to the role of the data
Use population variance when the entered values are the complete population being described. The n minus one form is commonly used to estimate population variance from a sample under appropriate assumptions. Neither number diagnoses outliers, skewness, dependence or measurement quality. Review the distribution and study design, preserve units and document which definition appears in any comparison.
Frequently asked questions
Why are two variances shown?
Population variance divides by n, while sample variance divides by n minus one.
What units does variance use?
Variance uses squared versions of the original measurement units.
Where is standard deviation shown?
The third result is the square root of the sample variance.