Reviewed by CalcMulti Editorial Team·Last updated: ·← Geometry Hub
A sector is a "pie slice" of a circle — the region bounded by two radii and the arc between them. The area of a sector equals the fraction of the full circle determined by the central angle: A = (θ/360) × πr² for degrees, or A = ½r²θ for radians.
The arc length (the curved edge of the sector) is L = (θ/360) × 2πr for degrees, or L = rθ for radians.
Sectors appear everywhere: pie charts, pizza slices, clock hands, fan blades, and geographic sectors. This calculator finds sector area, arc length, and perimeter from the radius and central angle.
A = (θ / 360) × π × r²
Full circle area from radius, diameter, or circumference
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This calculator is for educational purposes only and does not constitute professional advice. Results are based on standard mathematical formulas. Always verify critical calculations with a qualified professional before making important decisions.