Quick answer
Each slice's share is value ÷ total × 100 and its angle is value ÷ total × 360°. Values of 30, 20 and 50 total 100, giving shares of 30%, 20% and 50% and angles of 108°, 72° and 180°.
Enter the values separated by commas. The calculator returns the total, percentages and slice angles. Use it to prepare the numbers for a pie chart.
Related tools: Triangle Calculator: Area, perimeter, angles and type of a triangle from its three sides. Circle Calculator: Radius, diameter, circumference and area of a circle from any one of them. Circumference Calculator: Circumference of a circle.
How to use the Pie Chart Calculator
- Type values, for example 30, 20, 50.
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Values | Text, such as 30, 20, 50 | — |
Formula and method
Formula
share = value ÷ total × 100; angle = value ÷ total × 360°
IEEE-754 double precision; shown to the decimals indicated.
Values must be positive.
Worked examples
These examples are verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Values = 30, 20, 50.
| Result | Value |
|---|---|
| Total | 100 |
| Shares | 30%, 20%, 50% |
| Angles | 108°, 72°, 180° |
Example 2
Inputs: Values = 1, 1.
| Result | Value |
|---|---|
| Total | 2 |
| Shares | 50%, 50% |
| Angles | 180°, 180° |
The first line is the headline result (total). Below it the pie Chart Calculator lists shares and angles, which describe the same case from other angles. IEEE-754 double precision; shown to the decimals indicated.
Drawing the chart
Use the angles to draw a protractor-style pie: start at 12 o'clock and add each slice's angle clockwise. Angles add up to 360°.
When a pie chart is the wrong choice
Pie charts work for a few categories (up to about 5) that make up a whole. With many categories or small differences, a bar chart is easier to read. Negative values cannot be shown on a pie chart.
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Values: left empty shows "Enter values." beside that field and no result.
Choosing between the Pie Chart Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Triangle Calculator](/math/triangle-calculator/) | side a, side b and side c | Area |
| [Circle Calculator](/math/circle-calculator/) | i know the and value | Area |
| [Circumference Calculator](/math/circumference/) | i know the and value | Circumference |
| [Area of a Circle Calculator](/math/area-of-a-circle/) | i know the and value | Area |
| [Rectangular Prism Volume Calculator](/math/rectangular-prism-volume/) | length, width and height | Volume |
Assumptions and limitations
- Needs at least one positive value
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for values to confirm this.
Frequently asked questions
Do values have to be percentages?
No, any positive numbers; they are normalised.
What if the total is not 100?
The shares are still calculated from the total.
Does it draw the chart?
It returns angles and percentages.
What does the Pie Chart Calculator calculate?
Shares and slice angles for a set of values. It returns Total, Shares and Angles.
What formula does the Pie Chart Calculator use?
share = value ÷ total × 100; angle = value ÷ total × 360°. Values must be positive.
What do I need to enter in the pie Chart Calculator?
You enter Values.
How is the result rounded or limited?
IEEE-754 double precision; shown to the decimals indicated. Needs at least one positive value.
What is an example of a pie Chart result?
With values 30, 20, 50, the total is 100.
Related calculators
- Triangle Calculator — Area, perimeter, angles and type of a triangle from its three sides.
- Circle Calculator — Radius, diameter, circumference and area of a circle from any one of them.
- Circumference Calculator — Circumference of a circle.
- Area of a Circle Calculator — Area of a circle from its radius, diameter or circumference.
- Rectangular Prism Volume Calculator — Volume of a rectangular prism (box).
- Trigonometry Calculator — All six trigonometric functions of an angle.
Sources
- OpenStax, Prealgebra 2e (Rice University): fractions, decimals, percents, ratios and rounding
- NIST Special Publication 811, Guide for the Use of the International System of Units (SI)
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.