Histogram maker
Paste your raw numbers — no need to count them first. ChartCraft picks sensible bins, draws the histogram and gives you the frequency table and summary statistics.
Paste raw numbers — separated by spaces, commas, tabs or new lines. Don’t count them first; the tool does that.
Labels & options
| Bin | Count | Relative |
|---|---|---|
| 10 – <20 | 5 | 16.7% |
| 20 – <30 | 11 | 36.7% |
| 30 – <40 | 9 | 30% |
| 40 – <50 | 3 | 10% |
| 50 – <60 | 2 | 6.7% |
| Group | n | Min | Q1 | Median | Q3 | Max | Mean | SD |
|---|---|---|---|---|---|---|---|---|
| Data | 30 | 12 | 22 | 28.5 | 36 | 58 | 30.17 | 11.06 |
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How to make a histogram
- Paste the raw values, separated by spaces, commas or new lines (a spreadsheet column works).
- Leave bins at 0 for automatic Sturges’ rule bins, or set a number of bins or an exact bin width.
- Read the frequency table and the five-number summary under the chart.
- Add a frequency polygon if you need one, then download PNG or SVG.
Same data, different bin width
30 commute times in minutes. Drag the bin width and watch the shape change — the data never does.
Width 2 shows mostly noise; 25 squashes everything into two bars. Around 5–10 shows the real story: most people commute 20–35 minutes, with a long tail to the right.
How the bins are chosen
With bins set to 0, the tool uses Sturges’ rule: k = ⌈log₂(n) + 1⌉ bins for n values, then rounds the width to a friendly number (1, 2, 2.5, 5 × a power of ten) so the edges land on round values. Each bin includes its left edge and excludes its right edge, except the last bin, which includes the maximum. You can override with a number of bins or an exact width.
The bin width changes the story. Too few bins hide the shape; too many make noise. Drag the slider in the explainer to see it happen.
Reading the shape
- Symmetric / bell-shaped: mean ≈ median.
- Right-skewed (long tail to the right, like incomes or commute times): mean > median.
- Left-skewed: mean < median.
- Two peaks (bimodal): often two groups mixed together.
Want to see every value? Try a dot plot or stem-and-leaf plot. Comparing groups? A box plot is more compact.
Questions
How many bins should a histogram have?
There is no single right answer. Sturges’ rule (used here by default) works well for up to a few hundred values; the square-root rule (√n bins) is a common alternative. Try a few and choose the one that shows the shape without noise.
Why are there no gaps between the bars?
Because the bins cover a continuous range: one bin ends exactly where the next starts. Gaps are for bar graphs of separate categories.
Can I make a histogram from a frequency table?
This tool expects raw values. If you only have counts per range, use the bar graph maker with the ranges as categories, and set the direction to vertical.
What is a frequency polygon?
A line joining the midpoints of the tops of each bar, closed at zero on both ends. Tick “Frequency polygon” to overlay one.