Variance Calculator
Spread around the mean.
Enter the values and press Calculate.
How to use Variance Calculator
Variance measures how far numbers sit from their mean, on average. This tool uses the population formula.
Open Variance Calculator on toolpermarket and enter your values above.
Enter a list of numbers separated by commas in the fields above, then press Calculate.
Read the result below the form. You can change any input and press Calculate again to compare scenarios.
Worked example. For 2, 4, 4, 4, 5, 5, 7, 9 the variance is 4.
When to use Variance Calculator. Use it in statistics, quality control, or any study of consistency.
When you actually reach for this
- Use it in statistics, quality control, or any study of consistency.
Where this tool stops being accurate
- Uses exactly the values you enter; one typo or outlier swings the result.
- It does not test whether your sample is representative or large enough to mean anything.
Frequently asked questions
Population or sample variance?
This tool divides by the count of values, the population formula. Sample variance divides by count minus one.
Why square the differences?
Squaring keeps values positive and weights larger gaps more, which is why variance is in squared units.
Why does an outlier change it so much?
Statistics like the mean and range respond directly to extreme values; the median is more stable, which is why both are shown where relevant.