Enter values and select Calculate to see your result.
Calculate sample or population standard deviation, variance and mean
Separate numbers with commas, spaces or new lines. Sample variance divides by n−1; population variance divides by n.
How to use the Standard Deviation Calculator
Calculate mean, variance and standard deviation for a population or sample.
- Enter numbers separated by commas, spaces or new lines.
- Choose Population or Sample.
- Calculate mean, variance and standard deviation.
Standard Deviation Calculator formula
Population variance divides squared deviations by n; sample variance divides by n − 1; standard deviation is its square root.
Worked example
Inputs: Population values 2, 4, 4, 4, 5, 5, 7 and 9.
What to expect: The mean is 5 and population standard deviation is 2.
How to read your result
Standard deviation uses the same unit as the data; a larger value means more spread.
Frequently asked questions
Which mode should I choose?
Use Population for every group member and Sample for a sample of a larger group.
Why do results differ?
Sample variance uses n − 1 to reduce estimation bias.