Sector Area Calculator
Enter the radius and the angle of a circular sector to calculate its area and arc length.
Sector Area Calculator
Calculate the area and arc length of a circular sector (a 'pie slice' of a circle) given its radius and angle.
This calculator provides an estimate for general informational purposes only. It is not a substitute for professional financial, mechanical or engineering advice.
A circular sector is the 'pie slice' bounded by two radii and an arc; both its area and arc length are simply the corresponding fraction of the full circle's area or circumference.
Example
- With the default values shown above, this calculator returns: Sector Area ≈ 78.54; Arc Length ≈ 15.71.
Frequently Asked Questions
What is the formula?
Sector Area = (Angle ÷ 360) × π × Radius². Arc Length = (Angle ÷ 360) × 2π × Radius — both are just the fraction of the full circle the angle represents.
What if my angle is in radians?
Convert radians to degrees first by multiplying by (180 ÷ π ≈ 57.2958), then enter the degree value here.