Math & Statistics

Frequency Distribution Calculator

Bins numbers into a frequency table with counts, percentages and a text histogram.

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How to use this tool

  1. Paste your numbers, one per line.
  2. Leave the bin count on automatic for the first run.
  3. Select Distribute.
  4. Re-run with a different bin count. If the shape holds, it is in the data rather than in the bins.

What frequency distribution does

The shape a histogram appears to have depends on the bin width, which is why two people can look at the same data and see one hump or two. Left on automatic this page uses the Freedman–Diaconis rule, which sizes bins from the interquartile range and so is not thrown off by a long tail, and falls back to Sturges when the interquartile range collapses to zero.

Set the bin count by hand and re-run it before you draw any conclusion from the shape — if the story survives three bin counts it is probably in the data, and if it does not it was in the bins. Each row carries the count, the share of the total and a bar drawn in text, so the table can be pasted into a ticket or a commit message and still read as a distribution.

Frequently asked questions

By the Freedman–Diaconis rule, which sets the bin width from the interquartile range and the number of observations. It is chosen over the simpler Sturges rule because it is far less distorted by a long tail. When the interquartile range is zero, because most values are identical, it falls back to Sturges.

Because binning is a summary, and every summary discards something. Too few bins hide a second cluster; too many turn ordinary noise into apparent structure. Running two or three bin counts and keeping only what appears in all of them is the standard defence.

Yes. The result downloads as CSV with the bin range, the count and the percentage, so it can go straight into a spreadsheet or a report. The text bars are there for pasting into a ticket where an image would not survive.