Cumulative Frequency Calculator

Cumulative frequency is a running total of frequencies up to and including a given class or value in a dataset. For each class, you add its frequency to the sum of all previous class frequencies. It tells you how many data points fall at or below a certain value.

Cumulative frequency helps you understand the distribution of data and quickly determine what proportion of observations fall below a certain threshold. It is widely used in statistics, quality control, and data analysis to identify medians, quartiles, and percentiles within a dataset.

Use a cumulative frequency calculator any time you need to organize raw numerical data into a grouped frequency distribution, visualize how values accumulate across classes, or calculate percentiles and quartiles. It is especially useful when dealing with large datasets where manual counting would be tedious.

Relative frequency is the proportion of observations in a single class, calculated as the class frequency divided by the total number of data points. Cumulative relative frequency is the running total of these proportions — it shows what fraction of all observations fall at or below the upper boundary of each class.

Class intervals are determined by dividing the range of your data (maximum minus minimum) by the number of classes. This calculator auto-calculates the number of classes using Sturges' rule (k = 1 + 3.322 × log₁₀(n)) if you don't specify one, and then computes a uniform class width from that.

Simply type or paste your numeric values into the Data Values box, separated by commas or spaces. For example: 4, 7, 13, 2, 19, 7. The calculator will parse the values, sort them, build the class intervals, and compute all frequency columns automatically.

Yes. By default the calculator uses Sturges' rule to choose an appropriate number of classes for your dataset. However, you can override this by entering any integer between 2 and 20 in the Number of Classes field, and the table will rebuild using your specified value.

An ogive (pronounced 'oh-jive') is a line graph that plots cumulative frequency (or cumulative relative frequency) against the upper boundary of each class interval. It gives a smooth curve showing how data accumulates and is useful for visually estimating medians and percentiles.