Sector Area Calculator
Calculate the area of a pie-slice (sector) of a circle from its radius and angle.
Calculate
Enter your values below.
Result
Sector area
0
Formula used
Sector area = πr² × (angle ÷ 360)
Example: Radius 10, angle 90° → sector area ≈ 78.54.
How to use this calculator
- Enter Radius, Angle (degrees).
- Press Calculate to see your result instantly.
FAQ
Frequently asked questions
What is a sector?
A 'pie-slice' shaped portion of a circle, bounded by two radii and an arc.
What if the angle is 360°?
The sector area equals the full circle's area.
Can I use radians instead of degrees?
This calculator expects degrees; convert radians to degrees first (multiply by 180/π).
How is this related to arc length?
Both scale with angle ÷ 360, but arc length measures the curved edge, not the enclosed area.