Histogram maker

Paste your numbers and pick how many intervals (bins) to use, or leave it on auto. The tool draws equal-width bars and lists every interval with its count, so you can copy the frequency table.

NumbersSeparated by commas, spaces or new lines.

Number of intervalsA whole number from 1 to 40, or auto for Sturges' rule: ⌈log₂ n⌉ + 1.

Intervals5

Interval width: 2
Values: 15
Tallest interval (count): 4 to 6 (4)
2 to 4): 3
4 to 6): 4
6 to 8): 3
8 to 10): 3
10 to 12]: 2

Runs in your browser: nothing you enter is sent anywhere.

How to use it

Paste your numbers.
Leave the interval count on auto or type a number.
Read the chart and the table of counts below it.

How it works

The width is (max − min) / bins. A value x goes into interval number ⌊(x − min) / width⌋, with the maximum placed in the last one. The chart height is scaled to the tallest bar.

Worked example

Values 0, 1, 2, 3, 4 with 2 intervals: the width is 2, so [0, 2) holds 0 and 1 and [2, 4] holds 2, 3 and 4. The counts are 2 and 3.

Tips

Compare the same data with two or three bin counts before drawing conclusions about its shape.
Above 20 bins the counts are not printed on the bars, but the table still lists them.

Frequently asked questions

How many bins should I use?

There is no single right answer. Sturges' rule, ⌈log₂ n⌉ + 1, is a common starting point for small samples. Try a few values: too few hides the shape, too many makes it noisy.

Which interval does a boundary value fall into?

Intervals are closed on the left and open on the right, like [2, 4). The very last interval is also closed on the right so the maximum is counted.

Are the bars equal in width?

Yes. The range from the smallest to the largest value is divided into equal intervals.

Can I use my own interval edges?

Not in this version. Intervals always start at the smallest value.

More in Math

All tools in this category: Math ·Updated November 3, 2026