Circle Area Calculator
Need to solve for area? Just input any one known property below (radius, diameter, circumference, or area) to instantly calculate the rest.
1. Select Known Metric
2. Enter Value & Unit
radius
Results
Radius(r)Input
d / 2
0.0000cm
Diameter(d)
2 × r
0.0000cm
Circumference(C)
2 × π × r
0.0000cm
Area(A)
π × r²
0.0000cm²
Formula calculations verified.Pi constant: 3.1415926535...