Calculated result
Enter measurements and select Calculate.
Formula
Sector area = ½r²θ when θ is measured in radians, equivalent to πr² × angle ÷ 360 for degrees.
Ownership boundary
This page owns partial-circle sector area. The general Area Calculator remains the owner for full circles and other common shapes.
Worked example
The editable example values above demonstrate the formula and expose each assumption used in the result.