Circle Calculator

Enter any one measurement of a circle to calculate all others.

Radius5
Radius (r)5
Diameter (d = 2r)10
Area (A = πr²)25π ≈ 78.53981634
Circumference (C = 2πr)10π ≈ 31.41592654

Formulas:

Area formulaA = π × r² = π × 5² = 78.53981634
Circumference formulaC = 2 × π × 5 = 31.41592654