Math

Sector Area Calculator

Area of a pie slice of a circle.

Enter your values

Results update instantly as you type — no submit needed.

Results
Sector area
52.3599
Arc length
10.472
Segment area
9.0586
Chord length
10
Share of full circle
16.67%

Quick answer

A sector's area is half the radius squared times the angle in radians.

A = ½r²θ

How to use the Sector Area Calculator

  1. 1Enter the circle radius.
  2. 2Enter the sector's central angle in degrees.
  3. 3Read sector and segment areas.

Frequently asked questions

What is a segment?

The region between a chord and the arc — the sector minus the triangle.

How do I get the angle from the arc?

Divide arc length by radius for radians.