The Excel STDEV function returns the standard deviation for data that represents a sample. To calculate the standard deviation for an entire population, use STDEVP or STDEV.P.


Get the standard deviation in a sample

Return value 

Estimated standard deviation


  • number1 - First number or reference in the sample.
  • number2 - [optional] Second number or reference.

How to use 

The STDEV function calculates the standard deviation for a sample set of data. Standard deviation measures how much variance there is in a set of numbers compared to the average (mean) of the numbers. The STDEV function is meant to estimate standard deviation in a sample. If data represents an entire population, use the STDEVP function.

In the example shown, the formula in F7 is:


Note: Microsoft classifies STDEV as a "compatibility function", now replaced by the STDEV.S function.

Standard Deviation functions in Excel

The table below summarizes the standard deviation functions provided by Excel.

Name Data set Text and logicals
STDEV Sample Ignored
STDEVP Population Ignored
STDEV.S Sample Ignored
STDEV.P Population Ignored
STDEVA Sample Evaluated
STDEVPA Population Evaluated


  • STDEV calculates standard deviation using the "n-1" method.
  • STDEV assumes data is a sample only. When data represents an entire population, use STDEVP or STDEV.P.
  • Numbers are supplied as arguments. They can be supplied as actual numbers, ranges, arrays, or references that contain numbers.
  • STDEV ignores text and logical values that occur in references, but evaluates text and logicals hardcoded as function arguments.
  • To evaluate logical values and/or text in the calculation, use the STDEVA function.
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Dave Bruns

Hi - I'm Dave Bruns, and I run Exceljet with my wife, Lisa. Our goal is to help you work faster in Excel. We create short videos, and clear examples of formulas, functions, pivot tables, conditional formatting, and charts.