Frequency Distribution Calculator

A frequency distribution is the first step in making sense of a set of numbers, and this calculator builds one for you from any data you paste in. Instead of staring at a long list of values, a frequency distribution groups them into class intervals, equal-width bands across the range of the data, and counts how many values fall into each, turning raw numbers into a clear, compact table that reveals the shape of the data at a glance: where it clusters, how widely it spreads, and whether it leans to one side. Enter your data separated by commas or spaces, choose how many classes you want, and the calculator returns a full table with each class interval, its frequency, its relative frequency as a percentage of the total, and the cumulative frequency, the running total as you move down the classes. It also reports the count, the range and the mean so you have the key summary figures in one place. Those columns each earn their keep. The frequency shows the raw count in each band, the relative frequency shows the share of the data, which is ideal for comparing groups of different sizes, and the cumulative frequency is the basis for finding medians, quartiles and percentiles, and for drawing an ogive. Choosing the number of classes is part of the craft: five to ten suits most data sets, with a common rule of thumb being about the square root of the number of values. This makes the tool genuinely useful for statistics students organising data, for anyone summarising survey results, test scores or measurements, and as a quick way to prepare data for a histogram. Because it recalculates as you change the data or class count, you can see how the grouping affects the picture. The method and a worked example are explained below.

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