Statistics calculator
Mean, median and standard deviation of a list.
About this calculator
Paste or type numbers separated by spaces or commas to get the main summary statistics at once.
Use the sample standard deviation when your numbers are a sample from a larger group, and the population figure when they are the entire group.
How it works
Sample standard deviation divides by n − 1, and suits data drawn from a larger group. Population divides by n.
Worked example
- Numbers, separated by spaces or commas: 4, 8, 15, 16, 23, 42
Mean: 18 (6 values)
The story behind it
Where the idea came from: Karl Pearson, English mathematician, who introduced the term standard deviation in the 1890s.
The idea of measuring spread is older than its name. Pearson gave it the name we still use, and the n − 1 used for samples is known as Bessel's correction, after the German astronomer Friedrich Bessel. This calculator gives both versions so you can choose the one that fits your data.
Why you can trust this calculator
- It runs in your browser. Nothing you type into it is sent anywhere.
- The method is explained on this page, so you can check it yourself.
- Free to use, with no sign-up.
- Results are estimates, so please double-check anything important.
- Spotted a mistake? Tell us and we'll look into it.
After 15 years as a mathematics educator, I built CalculStore to give students, teachers, professionals and anyone working with numbers simple, reliable tools.
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