Standard deviation calculator
Paste a list of numbers to get the standard deviation and every other summary statistic.
How it’s worked out
- Mean
- Sum of squared deviations
- Variance
- Standard deviation
Questions people ask
Sample or population?
Use “sample” when your numbers are a selection from a bigger group (most real data). It divides by n − 1, which corrects for the sample’s tendency to understate spread. Use “population” only when you have every member of the group.
What does standard deviation mean?
It is the typical distance of values from the mean. For roughly bell-shaped data, about 68% of values fall within one standard deviation of the mean and 95% within two.