Circle Area Calculator
Enter radius on Jenzzy for exact circle area and perimeter using π.
Inputs
Results
Enter values to see results.
Formula
A = πr²; C = 2πr
Diameter d = 2r; area grows with the square of radius.
Example
- Area: π × 49 ≈ 153.94
- Circumference: ≈ 43.98= 153.94 sq units
Result: Area ≈ 153.94 square units
Frequently Asked Questions
Units?
Area uses square units of the radius.
Diameter input?
Halve diameter to get radius.
Sector?
Multiply full area by angle/360 for partial circles.