What is the Pie Chart Percentage Calculator?
A pie chart shows how individual parts compare to a whole, where the entire circle represents 100% (or 360°). This calculator converts any single value into its percentage share of a total, and also returns the exact slice angle in degrees so you can draw the chart accurately by hand or in any graphics tool.
How to use it
Enter the value of the slice you care about and the total (the sum of all values). The calculator divides the value by the total, multiplies by 100 for the percentage, and by 360 for the slice angle. Both results update instantly.
The formula explained
The core relationship is percentage = (value ÷ total) × 100. Because a full circle is 360°, the matching slice angle is degrees = (value ÷ total) × 360. Every percentage point equals 3.6 degrees, so 25% is always a 90° quarter slice.
$$\text{Percentage} = \frac{\text{Value}}{\text{Total}} \times 100\%$$
$$\text{Degrees} = \frac{\text{Value}}{\text{Total}} \times 360^{\circ}$$
Worked example
Suppose 45 of 360 survey respondents chose option A. The percentage is $$(45 \div 360) \times 100 = 12.5\%,$$ and the slice angle is $$(45 \div 360) \times 360 = 45^{\circ}.$$ So option A occupies a 45-degree wedge that fills one-eighth of the chart.
FAQ
Why does the angle matter? When drawing a pie chart manually, you need the central angle to mark each wedge with a protractor.
What if my total is the sum of several categories? Add all category values together to get the total, then run each category through this calculator to get its percentage.
Can the percentage exceed 100%? Only if the value is larger than the total, which usually means the total was entered incorrectly.
