Pie Chart Angle Calculator
Last reviewed on 2026-05-22.
Convert between percentages and degrees of arc
The math
A full pie chart spans 360°. Each 1% of the pie equals 3.6° of arc. To convert a percentage to degrees, multiply by 3.6. To convert degrees back to a percentage, divide by 3.6.
Common values
- 10% = 36°
- 25% = 90° (a quarter pie)
- 33.3% = 120° (a third)
- 50% = 180° (half)
- 66.7% = 240° (two-thirds)
- 75% = 270°
Why this matters for chart builders
If you're drawing a pie chart by hand, in SVG, or in Canvas, you'll need the angle in degrees (or radians) rather than the raw percentage. Use this calculator to convert between the two without doing the multiplication in your head.
Tip: For radians instead of degrees, multiply the percentage by 0.0628 (or convert degrees to radians by multiplying by π/180).
Equals — degrees of arc.
Equals — percent of the pie.
Frequently Asked Questions
How do I convert a pie chart percentage to degrees?
Multiply the percentage by 3.6. A 25% slice equals 90° of arc; a 50% slice equals 180°; a full pie is 360°.
How do I convert degrees back to a percentage?
Divide the degrees by 3.6. A 90° slice is 25% of the pie; a 180° slice is 50%.
What about radians?
Multiply the percentage by 0.0628 (which is 2π/100) to get radians. A 25% slice is 1.57 radians (π/2).