Circle Sector Area Calculator
Formula
Area = (π × r² × angle) / 360
About This Calculator
Circle Sector Area Calculator is designed to reduce manual errors and give repeatable outputs when you need quick, reliable answers.
Calculate the area of a circle sector from radius and angle for geometry, design, and engineering layout tasks.
If your workflow expands, pair this calculator with Triangle Area Calculator and Volume of a Sphere Calculator to cross-check assumptions and build a stronger analysis chain.
Formula
Sector Area = (theta / 360) * pi * r^2
Example Calculation
The worked example below demonstrates how the input fields translate into the final output. Use it as a quick validation pass before entering your own numbers.
- radius: 10
- angleDegrees: 90
Explanation of Results
Result Interpretation
A 90-degree sector is one quarter of a circle, so area is one quarter of full circle area.
FAQ
Can I use radians instead of degrees?
Yes, if supported by input mode. In radian form, area is (1/2) * r^2 * theta.
How is sector area different from arc length?
Sector area measures enclosed region size; arc length measures the curved boundary distance.
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See Also
Other calculators in Geometry