Pie Chart and Bar Graph Calculator
Turn a small table of data into a pie chart and a bar graph (or a double bar graph), with each slice's percentage and central angle worked out exactly.
About the Pie Chart and Bar Graph Calculator
A pie chart shows how a whole is shared: each category's slice has central angle value ÷ total × 360°. A bar graph compares the values directly, and a double bar graph puts two series side by side, like marks in two tests.
The angles are shown as exact fractions, so you can draw them with a protractor to the nearest degree.
The formula
central angle = value ÷ total × 360°; percent = value ÷ total × 100
Worked example
Rent 8000 of a 24000 budget
- 8000 ÷ 24000 × 360° = 120°
- So the rent slice is 120°, a third of the circle.
Questions people ask
Do the angles always add to 360°?
Yes, exactly, because the shares add to the whole. Rounded angles may be off by a degree.
When is a bar graph better?
When you want to compare sizes or show a change, or when the parts don't make up a single whole.