STDEV.P Function

Excel 2010+ Statistical

The Excel STDEV.P function calculates the standard deviation of an entire population — a measure of how spread out the values are, dividing by n rather than n−1.

Quick answer:

=STDEV.P({2,4,4,4,5,5,7,9}) population standard deviation = 2

Syntax

=STDEV.P(number1, [number2], ...)

Argument		Description
`number1`	Required	The first number, array, or range representing the population.
`number2, ...`	Optional	Up to 254 additional numbers, arrays, or ranges.

How to use it

STDEV.P measures the spread of data when your values represent the whole population. It divides the sum of squared deviations by n (not n−1).

=STDEV.P({2,4,4,4,5,5,7,9}) // population spread = 2

=STDEV.S({2,4,4,4,5,5,7,9}) // sample spread =~ 2.138

Compared with the sample version STDEV.S, STDEV.P gives a slightly smaller number because dividing by n instead of n−1 makes the denominator larger. STDEV.P is the square root of VAR.P.

Population or sample? Use STDEV.P only when your data covers every member of the group. If it is a sample drawn from a larger population, use STDEV.S so the spread is not underestimated.

Try it: interactive demo

Live demo

Pick a STDEV.P example to see the formula and its result.

example

Result:

Practice workbook

📊

Download the free STDEV.P practice workbook

Every example on this page, ready to open in Excel — plus practice challenges with answers on a separate tab. No sign-up required.

Frequently asked questions

What is the difference between STDEV.P and STDEV.S?

STDEV.P divides by n (use it when your data is the entire population); STDEV.S divides by n−1 (use it for a sample of a larger population). STDEV.S returns a slightly larger value.

When should I use STDEV.P?

Use STDEV.P only when your data includes every member of the population — for example every employee in a company, not a survey sample.

Does STDEV.P ignore text and logical values?

Yes. In a referenced range, text, logical values, and empty cells are ignored. To include text-as-0 and TRUE-as-1, use STDEVPA instead.

How does STDEV.P relate to VAR.P?

Standard deviation is the square root of variance, so =STDEV.P(data) equals =SQRT(VAR.P(data)) for the same data.

Master functions like this in one day

This page covers one function. Our Excel Formulas and Functions class covers the 30 that matter most — live, hands-on, taught by professionals in Dallas–Fort Worth, Houston, Austin, Oklahoma City, Denver, or online.

See the Formulas & Functions Class

Related functions: STDEV.S · VAR.P · VAR.S · STDEVPA · AVERAGE