Maths & numbers
Circular sector calculator
Calculate a sector’s area, arc and perimeter.
A clear answer. Here’s how.
For a sector strictly between 0 and 360 degrees, area = πr²θ/360, arc = 2πrθ/360 and perimeter = arc + 2r. The two straight radii form part of the boundary.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Radius
- 5
- Central angle (degrees)
- 90
Example result
- Sector area
- 19.6349540849
- Arc length
- 7.85398163397
- Sector perimeter
- 17.853981634