Compute both sample and population standard deviation from a list of numbers, along with variance, mean, and count, the core measures of spread in statistics.
How it works
- Paste your comma-separated list of data points.
- The statistical engine measures every variance from the mean.
- Read the detailed breakdown of sample vs population standard deviations.
Frequently asked questions
Sample or population standard deviation?
Use sample (n-1) when your data is a subset of a larger group, population (n) when it is the entire group.
What does standard deviation tell me?
How spread out values are. A small SD means values cluster near the mean; a large SD means they are widely scattered.
Why square the differences?
Squaring removes negative signs and weights larger deviations more heavily, then the square root returns to the original units.