Frequency Distribution Calculator

A frequency distribution is a summary of how often each value (or range of values) appears in a dataset. It organizes raw data into a table showing each value or class interval alongside its count, making patterns and trends easy to spot.

An ungrouped (or exact-value) distribution counts how many times each individual value appears — best for small datasets with few unique values. A grouped distribution buckets data into class intervals (e.g. 10–20, 20–30), which is more practical for large datasets with many distinct values.

A common rule of thumb is 5–10 classes. Sturges' Rule provides a formula: k = 1 + 3.322 × log₁₀(n), where n is your sample size. This calculator applies that rule automatically, but you can override it with your preferred number of classes.

Relative frequency is a class's frequency divided by the total number of observations, expressed as a percentage. It lets you compare distributions of different sizes and is essential for probability and statistical inference.

Cumulative frequency is a running total of frequencies from the first class up to and including the current one. The last cumulative frequency always equals the total sample size (n). It's used to determine how many observations fall below a given value.

The midpoint (or class mark) is the average of a class interval's lower and upper boundaries: midpoint = (lower limit + upper limit) / 2. Midpoints represent the entire class in calculations like the mean of grouped data.

Type or paste your numbers into the dataset field, separated by commas, spaces, or line breaks. The calculator parses any mix of these delimiters, so you can copy data directly from spreadsheets or text files.

The mode is the value (in ungrouped data) or the class interval (in grouped data) that occurs most frequently. In a frequency table, the modal class is the one with the highest frequency count.