About this calculator
The calculator also gives the chord and the segment between the chord and the arc.
How to use it
- Enter the radius.
- Enter the angle.
- Read the results.
The formula
Area = (θ ÷ 360) × πr²; arc = (θ ÷ 360) × 2πr
- θ
- angle in degrees
Worked example
Radius 10, angle 60°
- Area ≈ 52.36; arc ≈ 10.47.
- Chord = 10; segment area ≈ 9.06.
What the result means
A 90° sector is a quarter of the circle.
Assumptions
- All lengths in the same unit.
Limitations
- Results are rounded to 10 significant figures.
Frequently asked questions
How do I find the area of a sector?
(θ/360) × πr².
How do I find arc length?
(θ/360) × 2πr.
What is a segment?
The part between a chord and its arc.
Last reviewed on 3 October 2026. Found a mistake? Tell us.