Calculating Standard Deviation in Excel

Standard deviation is a statistical measure that helps you understand how spread out the data points in a dataset are. It quantifies the amount of variation or uncertainty in a set of values.

Calculating standard deviation in Excel

Excel provides two functions for calculating standard deviation, each suited for a specific type of data analysis:

  • STDEV.S: Calculates the standard deviation for a sample dataset. This function is used when your data represents a sample of the entire population.
  • STDEV.P: Calculates the standard deviation for an entire population. This function is used when your data includes every member of the population.

Syntax:

  • STDEV.S(number1, [number2], …)
  • STDEV.P(number1, [number2], …)

Arguments:

  • number1: Required. The first number in the range of data for which you want to calculate the standard deviation.
  • number2, …: Optional. Additional numbers in the range of data for which you want to calculate the standard deviation.

Example:

To calculate the standard deviation for the sample dataset in cells A1 to A10, you would use the following formula: =STDEV.S(A1:A10)

To calculate the standard deviation for the population dataset in cells A1 to A10, you would use the following formula: =STDEV.P(A1:A10)

Interpreting Standard Deviation:

The standard deviation is typically interpreted as follows:

  • Low standard deviation: The data points are close to the mean, indicating that the data is relatively uniform.
  • High standard deviation: The data points are spread out over a wide range, indicating that the data is more variable.

A high standard deviation indicates that the data is more variable, which can be useful for identifying outliers or anomalies. A low standard deviation indicates that the data is more uniform, which can be useful for making predictions.