Calculate the sample or population standard deviation and variance of a data set, with the mean, standard error and a step-by-step table.
About this tool
Calculate sample and population standard deviation and variance with steps.
How to use Standard Deviation Calculator
- Paste your numbers.
- Choose Sample or Whole population.
- Read the result and follow the table of deviations and squares.
Worked example
For 10, 12, 23, 23, 16, 23, 21, 16 the mean is 18 and the sample standard deviation is about 5.24.
What does standard deviation measure?
How spread out the values are around the mean. A small value means the data are close together.
Why divide by n − 1 for a sample?
It corrects the tendency of a sample to underestimate the spread of the whole population (Bessel’s correction).
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