Sector Area Calculator
Calculate the area of a circular sector from radius and central angle in degrees.
How to use
- Enter radius r.
- Enter the central angle in degrees and calculate.
Capabilities and scope
The tool takes the angle's fraction of 360° and applies it to the full circle area.
How it works
It uses A = πr² × θ/360.
Example
Radius 4 and angle 90° give 4π, about 12.5664.
Useful for
- Find the area of a pie-slice region
- Compare circular portions by central angle
Before you use it
- The angle input is in degrees; entering radians directly produces the wrong interpretation.
Frequently asked questions
What does 360° return?
It represents the full circle, so the result equals πr².