Frequency Distribution Calculator

Work out frequency distribution instantly with clear inputs, formula shown and shareable results.

About Frequency Distribution Calculator

A frequency distribution groups data into classes of equal width and counts how many observations fall in each. The class width is the range divided by the number of classes, and the modal class holds the most observations.

Formula

Class width

width = (maximum − minimum) / number of classes

Worked example

With the default values below, Frequency Distribution Calculator returns Frequency distribution of [3, 8.5): 3 [8.5, 14): 3 [14, 19.5): 2 [19.5, 25): 4. Change any input above and every figure here is recalculated in your browser.

Inputs used

Data values: 3, 7, 7, 12, 12, 12, 18, 18, 25, 25, 25, 25
Number of classesaccepts 1–30: 4

Results

Frequency distribution: [3, 8.5): 3 [8.5, 14): 3 [14, 19.5): 2 [19.5, 25): 4
Class width: 5.500000
Total observations: 12
Frequency of the modal class: 4

Step by step

1Values used
2Class width
3Frequency distribution= [3, 8.5): 3 [8.5, 14): 3 [14, 19.5): 2 [19.5, 25): 4
4Class width= 5.500000
5Total observations= 12
6Frequency of the modal class= 4

Assumptions and limits

The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How many classes should I use?

Sturges' rule suggests about 1 + log₂n, so roughly 4 or 5 classes for a dozen observations.

Are class intervals inclusive?

Here each class is half-open [lower, upper), with the top class closed so the maximum is included.