Pie Chart Angle Calculator

TOOL

Convert values or percentages into pie-slice angles in degrees — and convert degrees back to percentages.

Each value becomes a slice. Angle = (value ÷ total) × 360°. Separate with commas, spaces or new lines.

How pie chart angles work

A pie chart is a full circle, and a full circle is 360 degrees. That circle represents the whole — 100% of your data. Every slice's angle is just its share of that whole scaled onto the 360°.

From a percentage to degrees

Because 100% maps to 360°, one percent maps to 3.6°. So the rule is simply angle = percentage × 3.6. A quarter of the pie, 25%, is 25 × 3.6 = 90°. A 30% slice is 30 × 3.6 = 108°. The full pie, 100%, is 100 × 3.6 = 360°, as it must be.

From raw values to degrees

If you have counts rather than percentages, first add them to get the total. Each slice's angle is then (value ÷ total) × 360. You do not need to convert to percentages first — though the calculator shows the percentage too, for reference.

From degrees back to a percentage

Reverse the rule by dividing: percentage = angle ÷ 3.6. A 90° slice is 90 ÷ 3.6 = 25%, and a semicircle of 180° is exactly 50% of the pie.

Worked example

Suppose four slices hold the values 40, 30, 20, 10, summing to a total of 100. The first slice is (40 ÷ 100) × 360 = 144°, the second is (30 ÷ 100) × 360 = 108°, the third is 72°, and the last is 36°. Those four angles add back to 360°, the complete circle.

Turn the numbers into a chart

Once you know the angles, the easiest way to draw the slices accurately is to let a tool do it. The pie chart maker takes your labels and values, computes the angles for you, and exports a clean PNG or SVG. If you want to understand when a pie is the right choice in the first place, the pie chart guide walks through how to read one and the common mistakes to avoid.