CalculateMeasure

Math & Geometry

Sector Area Calculator

Calculate the area of a circular sector from radius and central angle.

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Calculator guide

How to use the Sector Area Calculator

Calculate the area of a circular sector from radius and central angle. Enter the requested values and select Calculate. The result and supporting values are produced locally in your browser.

Formula

Sector Area = (Angle ÷ 360°) × π × Radius²

Worked example

A 90° sector of a circle with radius 5 has an area of about 19.635 square units.

What to keep in mind

  • A 360° sector is the full circle; a 180° sector is a semicircle.

Methodology

This calculator uses deterministic arithmetic and performs the calculation locally in your browser. Verify assumptions, units, and source values for your specific use case.

Review standard: Level A · Standard formula. How calculator reviews work.

Frequently asked questions

What does this calculator calculate?

Calculate the area of a circular sector from radius and central angle.

How is the result calculated?

Sector Area = (Angle ÷ 360°) × π × Radius².

Can I use the result for an important decision?

Use the result as a calculation aid and verify the inputs, assumptions, and applicable professional or regulatory requirements before relying on it for an important decision.

Does CalculateMeasure store the values I enter?

The calculator performs its arithmetic in your browser. The calculator itself does not need to send your entered values to a server to produce the result.