The Power BI STDEV.P function is one of the DAX aggregate functions useful to calculate the standard deviation of the entire population. This article explains the DAX STDEV.P function that accepts the existing column (not the expression) to return the standard deviation of the entire population and the syntax is:

STDEV.P(<Column>)

The Power BI DAX STDEV.P function works only on the numeric values and assumes the column refers to the entire population. If it doesn’t have the entire population or sample of it, use the STDEV.S.

- The STDEV.P function uses the formula √[∑(x – x˜)2 / n] where x is the entire population, x˜ is the average, and n is the size of the population.
- While calculating the standard deviation of the entire population, the function will ignore the blank rows and it won’t be considered in the calculation.
- This function returns an error if the given column contains less than two non-blank rows.

## Power BI DAX STDEV.P function Example

We need a Measure to work with the STDEV.P function and to assign the standard deviation of the entire population. So, within the Home tab, click the New Measure button and rename it as ProfitSTDEVP. To demonstrate the DAX STDEV.P() function, use the Profit column from the SuperStore Orders table to obtain the standard deviation of the entire profit.

ProfitSTDEVP = STDEV.P(Orders[Profit])

Please add the new ProfitSTDEVP Measure to the table report. Similarly, create two more measures to calculate the standard deviation of the Sales and orders. Please refer to the Aggregate and the function article for the remaining Power BI functions. For more Charts >> Click Here.

SalesSTDEVP = STDEV.P(Orders[Sales])

OrdersSTDEVP = STDEV.P(Orders[Quantity])