# Standard Deviation Calculator

Here are the step-by-step calculations to work out the Standard Deviation (see below for formulas).

Enter your numbers below, the answer is calculated "live":

When your data is the whole population the formula is:

(The **"Population** Standard Deviation**"**)

When your data is a sample the formula is:

(The **"Sample** Standard Deviation**"**)

The important difference is "N-1" instead of "N" ... read more at Standard Deviation Formulas.