How to make a pie chart
The whole method is one formula: value ÷ total × 360°. Drag the sliders to see it work, then follow the steps by hand or online.
Step by step
- Check it’s one whole. The categories must not overlap and should add up to a meaningful total.
- Add up the values. Rent 850 + Food 320 + Transport 160 + Bills 210 + Savings 300 + Fun 160 = 2,000.
- Work out each share: 850 ÷ 2,000 = 0.425 = 42.5%.
- Convert to degrees: 0.425 × 360 = 153°. All slices together must make 360°.
- Draw from 12 o’clock, clockwise, largest slice first. Label each slice with its name and percentage.
The pie chart maker does steps 2–5 instantly and shows the full slice-maths table, handy for checking homework.
When not to use a pie
More than six slices, values that don’t form a whole, or comparing two pies side by side all work better as a bar graph.
How a number becomes a slice
Drag the amounts. Each slice’s angle is its share of the total × 360°.
Questions
How do I convert percentages to degrees for a pie chart?
Multiply the percentage by 3.6. 25% × 3.6 = 90°. Or, from raw values: value ÷ total × 360.
What if my percentages add up to more than 100?
Then the data is not parts of one whole: for example, a survey question where people could pick several answers. Use a bar graph instead.
How do I draw a pie chart by hand?
Draw a circle and a radius line from the centre to 12 o’clock. Use a protractor to measure each slice’s angle clockwise from the previous line, largest slice first.