The Excel STDEV.S function calculates the standard deviation for a sample set of data. STDEV.S replaces the older STDEV function, with the same behavior.


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.


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

Usage notes 

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

Note: STDEV.S replaces the older STDEV function, but has identical behavior. Although STDEV still exists for backwards compatibility, Microsoft recommends that people use the newer STDEV.S function instead.

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.S calculates standard deviation using the "n-1" method.
  • STDEV.S assumes data is a sample only. When data represents an  entire population, use the STDEV.P function.
  • Numbers are supplied as arguments. They can be supplied as actual numbers, ranges, arrays, or references that contain numbers.
  • STDEV.S ignores empty cells, logical values, and text that appears in supplied reference(s).
  • STDEV.S will evaluate text and logical values hardcoded as function arguments.
  • To evaluate logical values and/or numbers as text in a reference, see 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.