Histogram Maker

How to use the histogram maker

1. Type or paste your numbers, separated by spaces, commas or new lines, or choose a .csv or .txt file. Press Use example scores to see how it works.
2. Choose how to choose bins. Sturges, Scott and Freedman-Diaconis pick equal bins from the smallest to the largest number. Number of bins sets the count yourself, and Bin width makes bins that start on round multiples of the width, such as 0, 10, 20.
3. Decide where a number that sits exactly on a bin edge belongs, in the bin to its right or its left, and whether bars show counts or percent of all values. Add a title and a label if you like.
4. The histogram and a table of every bin appear as you type. Use Download PNG or Download SVG for the picture, Download CSV for the table, or Copy table for text.

Ten values in bins of width 10

Choosing the number of bins

Too few bins hide the shape of the data, and too many make it look ragged. The three automatic rules give a starting point. Sturges uses ceil(log2 n) + 1 bins, which suits small and fairly symmetric data. Scott's rule uses a bin width of about 3.49 times the standard deviation divided by the cube root of n. Freedman-Diaconis uses a width of 2 times the interquartile range divided by the cube root of n, which copes better with outliers. The number of bins is the range divided by that width, rounded up.

The results match numpy's histogram bin rules, checked on seven data sets. Equal bins run from the smallest to the largest value, and the last bin includes the largest value. With a set bin width, the edges are exact decimal multiples of the width, so 0.1 steps do not drift, and the tool adds bins until the largest value is inside the last bin. At most 200 bins are drawn.

Reading the chart and the table

Each bar covers one bin, and its height is the count or the share of values in it. Bars touch because the bins touch. The table lists each bin with its count, its share and the cumulative share, so you can see how many values are at or below each edge. Brackets show which edges are included: a square bracket includes the edge and a round one does not.

If you need the typical value and spread of the same data, use the descriptive statistics calculator, and for counts in a table without a chart, the frequency distribution calculator. To compare several groups side by side, the box plot maker draws one box per group.

Privacy and limits

The numbers are read and drawn in your browser. They are not uploaded. Up to 100,000 numbers are accepted, in plain decimal or exponent form. A number with thousands separators such as 1,234 is refused with a message, because a comma would otherwise split it into two numbers.

Assumptions and limits

• Bins are equal in width. Bins of different widths, and open-ended bins, are not offered.
• The automatic rules follow the formulas used by numpy, and a set number or width of bins is your own choice.
• When all values are equal, a single bin from half a unit below to half a unit above is drawn.
• Up to 100,000 numbers and 200 bins are used, and a file can be up to 1 MB.

Formulas reviewed October 10, 2026. See the calculation methodology for how SumPanda rounds, tests and sources its formulas.

Frequently asked questions