A pie chart shows how a whole is divided into parts. The full circle represents the total, and each category gets a slice whose angle – and therefore area – is proportional to its value. Pie charts work best for a handful of categories that together make up 100% of something: a household budget, market share, survey answers or the make-up of a population.
To draw one you need two numbers per category: its percentage of the total and its central angle. A category worth 1,200 out of 2,500 is 48% of the total, and 48% of 360° is 172.8°. This maker does those calculations for every line you enter and draws the chart at once.
Keep the chart readable: use no more than six or seven slices (merge small categories into “Other”), order slices from largest to smallest, and avoid pie charts when you need to compare categories of similar size – a bar chart shows small differences far more clearly. Never use a pie chart for values that do not add up to a meaningful whole.
How to use the Pie Chart Maker
- Categories – one “label, value” per line — Separate label and value with a comma, colon, semicolon or tab. Up to 30 categories.
- Order of slices
Everything is calculated in your browser, so results appear instantly and nothing you type is sent to a server.
How it works
Each line is read as “label, value”. The values are added to get the total; each value divided by the total gives its share, which is multiplied by 100 for the percentage and by 360 for the slice angle. Slices are drawn clockwise from 12 o’clock.
Worked example
A monthly budget of 2,500 is split into rent 1,200, food 450, savings 400, transport 200, utilities 150 and other 100. Rent is 1,200 ÷ 2,500 = 48% of the budget, so its slice is 0.48 × 360° = 172.8°. Food is 18% (64.8°), savings 16% (57.6°), transport 8% (28.8°), utilities 6% (21.6°) and other 4% (14.4°). The angles add up to 360° and the percentages to 100%.
Percentages and angles at a glance
| Percentage | Angle | Fraction of the circle |
|---|---|---|
| 5% | 18° | 1/20 |
| 10% | 36° | 1/10 |
| 12.5% | 45° | 1/8 |
| 20% | 72° | 1/5 |
| 25% | 90° | 1/4 |
| 33.3% | 120° | 1/3 |
| 50% | 180° | 1/2 |
| 75% | 270° | 3/4 |
Formula
Share = value ÷ total · Percentage = share × 100% · Central angle = share × 360°
Worked example
Inputs — Categories – one "label, value" per line: Rent, 1200
Food, 450
Transport, 200
Utilities, 150
Savings, 400
Other, 100; Order of slices: As entered.
Results — Largest slice = Rent – 48% of the total (172.8°); Pie chart table = Category Value Percent Angle
────────────────────────────────────
Rent 1,200 48% 172.8°
Food 450 18% 64.8°
Transport 200 8% 28.8°
Utilities 150 6% 21.6°
Savings 400 16% 57.6°
Other 100 4% 14.4°
Total 2,500 100% 360°; Total of all values = 2,500; Number of categories = 6; Largest category = Rent (48%); Smallest category = Other (4%).
Key terms
- Central angle
- The angle of a slice at the centre of the circle.
- Share (proportion)
- A category's value divided by the total.
- Categorical data
- Data that place observations into named groups.
Frequently asked questions
How do you calculate the angle for a pie chart?
Angle = value ÷ total × 360°. A category of 450 out of 2,500 gets 450 ÷ 2,500 × 360° = 64.8°.
How do you calculate the percentage of each slice?
Percentage = value ÷ total × 100%. 450 of 2,500 is 18%.
How many degrees is 1% of a pie chart?
3.6°, so 25% is 90° (a quarter) and 50% is 180°.
How many categories can a pie chart have?
Technically any number, but more than six or seven makes it hard to read. This maker accepts up to 30 and merges the smallest into "Other" on the chart when there are more than 12.
When should I not use a pie chart?
When values do not form parts of one whole, when categories are similar in size, or when you want to show change over time – use a bar or line chart instead.
Can a pie chart include negative values?
No. A slice cannot have a negative angle; show gains and losses with a bar chart.
What is the difference between a pie and a donut chart?
A donut chart is a pie with the centre cut out; the angles and percentages are calculated in exactly the same way.