Method
Calculate deviations from the mean, square them, average them, then take the square root. Sample deviation divides by n − 1.
Example
For 2, 4, 4, 4, 5, 5, 7, 9, population standard deviation is 2.
Limits
Check inputs and units. Important academic, financial or professional decisions should be confirmed against an appropriate source.
Common questions
What does the standard deviation calculator calculate?
Calculate population and sample standard deviation.
Does this standard deviation calculator show its method?
Yes. The result includes the central formula or working needed to check the answer.
Are my values uploaded?
No. The calculation runs in this browser and does not require an account.