Standard Deviation Calculator
Calculate the standard deviation, variance and mean of a data set, for both a population and a sample. The five-number summary, mode and interquartile range are included, along with a table of every deviation so you can check the working.
Population or sample?
Use the population figures when your data is the complete set you care about. Use the sample figures when your numbers are a subset drawn from a larger group, which is the usual case in experiments and surveys. The only difference is the divisor: the population variance divides by n, the sample variance by n − 1.
- Mean, sum and count
- Population and sample variance
- Population and sample standard deviation
- Median, mode, range and quartiles
- Deviation table showing every step
What the number means
The standard deviation is the typical distance of a value from the mean. A small standard deviation means the data clusters tightly around the average; a large one means it is spread out. It is measured in the same units as the original data, whereas the variance is in squared units.
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