Steps to Calculate Decile. Step 1: Firstly, determine the number of data or variables in the population or sample, which is denoted by n. Step 2: Next, sort all the data or variables in the population in ascending order. Download the Power BI 2018 NFL Stats and Analysis Report Dashboard here. So for this example I'm going to calculate the quartiles for NFL football players based on yards rushing. To calculate the quartile, we're going to use the PERCENTILEX.INC DAX function. The PERCENTILEX.INC function returns the number at the specified percentile.Can t take my eyes off you instrumental