Standard Deviation

Compute sample or population standard deviation, variance, and mean from a dataset. Free online calculator with formulas and step-by-step solutions.

About this tool

Compute sample or population standard deviation, variance, and mean from a dataset. Free online calculator with formulas and step-by-step solutions.

How to use this calculator

1. Choose the correct mode or direction before entering numbers.
2. Make sure your values match the expected units or date format shown in the fields.
3. Calculate once, then read both the final output and the supporting formula steps.
4. Round only after you understand the result so you do not lose useful precision too early.