Figure 2.4: Figure 2.1 Calculating Cumulative Frequencies for a Frequency Distribution One can calculate cumulative frequencies by “stair-stepping” up. The cumulative frequency in the bottom row is the same as the frequency for that row. Then add the frequency from the row above to find its cumulative frequency. Continue the process until one reaches the final row. Note that the cumulative frequency in the top row is the same as the number of cases in the data set.