Cumulative Frequency Calculator

About this calculator

Cumulative frequency is a running total: you take a list of class frequencies (how many data points fall into each category or interval) and, for each class, add its own count to the sum of every count that came before it. The last cumulative value always equals the total number of observations in the whole data set.

Plotting cumulative frequency against class boundaries produces what statisticians call an ogive, a smooth rising curve used to read off the median and quartiles graphically without needing the raw, ungrouped data — you simply find where the curve crosses the desired cumulative count and read across to the value. This makes cumulative frequency a standard tool in descriptive statistics courses and in summarizing survey or grouped measurement data where only bucketed counts are available.

Enter your class frequencies in order and this calculator builds the running cumulative total for you, one class at a time.