STDEV.P

The STDEV.P function calculates the standard deviation for 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.P function is meant to estimate standard deviation for an entire population. If data represents a sample, use the STDEV.S function. Note: STDEV.P replaces the STDEVP function, with identical behavior. Although STDEVP still exists for backwards compatibility, Microsoft recommends that people use the newer STDEV.P function instead. The table below summarizes the standard deviation functions provided by Excel.