Sector Area Calculator

Calculate sector area, arc length, and perimeter from radius and central angle. Supports both degrees and radians.

Input Values

010

Sector Diagram

rArcθArea
Radius (r)
Arc Length
Angle (θ)
Sector Area

Results

Sector Area (A)
0
A = ½r²θ
Arc Length (s)
0
s = rθ
Perimeter (P)
0
P = s + 2r
Angle Conversion
Degrees:0°
Radians:0 rad

Sector Formulas

A = ½r²θ
Sector area (θ in radians)
s = rθ
Arc length (θ in radians)
P = s + 2r
Perimeter of sector
θ° = θ × 180/π
Radians to degrees

About Sector Calculations

A sector is a "pie slice" portion of a circle, bounded by two radii and an arc. The sector area calculator helps you find the area, arc length, and perimeter of any sector when you know the radius and central angle.

Key Properties

  • Sector Area: The space enclosed by the sector
  • Arc Length: The curved edge of the sector
  • Perimeter: Total boundary length (arc + 2 radii)
  • Central Angle: Angle at the center of the circle

Common Angle Values

  • 90° = π/2 radians (quarter circle)
  • 180° = π radians (semicircle)
  • 270° = 3π/2 radians (three quarters)
  • 360° = 2π radians (full circle)