How to use the Histogram Maker
- 1. Paste your valuesEnter numbers separated by commas, spaces or new lines.
- 2. Choose the binsSet a bin width, a number of bins, or let Sturges' rule decide.
- 3. Make and downloadCreate the histogram and save it as PNG or SVG.
How bins are counted
A histogram splits the number line into equal-width bins and draws a bar for how many values land in each. Each bin includes its left edge and excludes its right edge, except the last bin, which includes the maximum. This matches NumPy's np.histogram and Excel's histogram chart.
Worked example (the default 30 exam marks, width 10, start 30): the bins 30–40 up to 90–100 hold 1, 3, 4, 8, 7, 4 and 3 values. The tallest bar is 60–70 (8 values), and the shape is slightly left-skewed, with a few low scores pulling the left tail out.
Choosing a good bin width
- Too wide and everything piles into two or three bars, hiding the pattern.
- Too narrow and the chart becomes spiky noise with empty gaps.
- Sturges' rule (k = 1 + log₂ n) is a sensible start for up to a few hundred values.
- Round edges such as multiples of 5 or 10 make the chart easier to read.
Look for the shape: symmetric and bell-like, skewed to one side, or with two peaks (bimodal), which often means two groups mixed together. A histogram is not a bar chart: bars touch because the bins are continuous ranges. The chart is drawn in your browser and nothing is uploaded. For the numbers behind the bars, use the frequency table maker; to compare groups, try the box plot maker.
Frequently asked questions
Can I paste a column from Excel?
Yes. Copy the cells and paste; each value on its own line is read correctly.
Why are my bins uneven at the end?
If you set a number of bins, the width is the range divided by that number, so edges may not be round. Set a width instead for round edges.
Is the Histogram Maker free?
Yes, the Histogram Maker is free. The first time you make your first histogram, you are asked for your name and WhatsApp number once. After that, this and every other Uncodemy tool opens straight away without the form.