Area of a Circle Calculator
Radius (r)
units
Diameter (d)
units
Circumference (C)
units
Results
Formulas Used
- Using Radius: A = πr²
- Using Diameter: A = π(d/2)²
- Using Circumference: A = C²/(4π)
Where π (pi) ≈ 3.14159
Area
-
Circumference
-
Radius
-
Diameter
-