Histogram Maker
Turn a list of numbers into a histogram with automatic or custom bins; download it.
About this tool
Paste your numbers, separated by spaces, commas or new lines, and the histogram appears straight away. Leave binning on automatic, or set the number of bins or an exact bin width. A frequency table lists each range and its count, and the chart downloads as SVG or PNG.
Choosing bins for a histogram
A histogram shows how numbers are spread out. It splits the range into equal-width bins and draws a bar for how many values land in each one. This reveals the shape that a list of numbers hides: whether the data is symmetric, skewed to one side, has two peaks or includes stray outliers. The bin width changes the picture a lot. Too few bins flatten everything into a block, and too many turn it into noise. Sturges' rule uses about log₂(n) + 1 bins, which suits modest, roughly bell-shaped data. For the 32 sample scores it gives six bins, which the tool rounds to a tidy width of 10. The Freedman–Diaconis rule sets the width from the interquartile range instead, so it copes better with skewed data and outliers. Each bin includes its lower edge and excludes its upper edge, except the last bin, which includes both. A histogram isn't a bar chart. Use bars with gaps for categories such as colours or countries, and a histogram for measurements. Honest limits: the starting edge and width you choose can shift the shape slightly, so try a couple of settings before drawing conclusions. The box plot maker, the chart maker and the standard deviation calculator are related.
Frequently asked questions
How many bins should a histogram have?
A common starting point is Sturges' rule, log₂(n) + 1. For skewed data, the Freedman–Diaconis rule usually gives a better width.
What's the difference between a histogram and a bar chart?
A histogram shows the distribution of numeric data in touching ranges. A bar chart compares separate categories.
Can I set my own bin width?
Yes. Choose 'Bin width' or 'Number of bins' and type the value you want.
Is my data saved?
No. The histogram is made in your browser and nothing is stored or sent.