# Excel STDEV.S Function

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.

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

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 |

Notes:

- 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.