Sector Area Calculator
Calculate the area of a circular sector.
How to Use the Sector Area Calculator
Enter the circle radius and central angle to calculate the area of a circular sector.
Practical Example
For radius 10 and a 90° angle, the sector is one quarter of the circle and has area about 78.54 square units.
Factors That Affect the Result
The angle must use the unit expected by the calculator, typically degrees. Radius must be positive and consistent with any related circle measurements.
Frequently Asked Questions
What is a sector?
It is the region bounded by two radii and their connecting arc.
Can the angle exceed 360°?
For a standard circle sector, use an angle from 0° to 360°.
How is sector area calculated?
Multiply circle area by angle divided by 360.
Related Tools
- Arc Length Calculator
- Circle Segment Calculator
- Circle Calculator
- Chord Length Calculator
- Area Calculator
Understanding Sector Area
A circular sector is the region enclosed by two radii and the connecting arc. When the central angle is measured in degrees, sector area is (angle ÷ 360) × πr².
The angle determines what fraction of the full circle is included, so confirm whether the input is in degrees or radians before calculating. Radius and output units must also be consistent. This formula assumes an ideal circle; real-world material layouts may need additional allowance for cutting, borders or measurement tolerance.
Understanding Sector Area
A circular sector is the portion of a circle enclosed by two radii and the connecting arc. Its area depends on the circle radius and the central angle. For degree-based angles, the usual formula is sector area = (angle ÷ 360) × πr², which scales the full circle area by the fraction of the circle represented.
Use the same length unit for the radius throughout the calculation. The resulting area will be expressed in the corresponding square unit. If an angle is supplied in radians, convert it first or use the appropriate radian formula.