Mean, median and standard deviation calculator
Paste or type your numbers separated by commas, spaces or semicolons. Everything is computed in your browser and nothing is stored.
Mean16.1250
- Median
- 15.0000
- Mode
- 15.0000
- Count
- 8
- Sum
- 129.0000
- Minimum
- 7.0000
- Maximum
- 31.0000
- Range
- 24.0000
- Standard deviation (sample)
- 7.6800
- Standard deviation (population)
- 7.1840
The formula
Mean = Σx / n. Sample standard deviation s = √(Σ(x − x̄)² / (n − 1)); the population figure divides by n instead.
Worked example
For 12, 15, 9, 22, 18, 15, 31, 7 the mean is 16.125, the median is 15, and the sample standard deviation is 7.6997.
How to use it
- 1Separators can be commas, spaces, semicolons or line breaks.
- 2Use the sample figure when your numbers are a sample of something bigger — that is the usual case.
- 3The mode is only reported when a value actually repeats.
Questions people ask
Sample or population standard deviation?
Use the sample figure (n − 1) unless your list is the entire population you care about. Spreadsheets call them STDEV.S and STDEV.P.
Why can the mean and median differ so much?
One extreme value drags the mean but barely moves the median. A large gap between them is a sign the data is skewed.
Last reviewed: 2026-10-20