Circle Calculator

Calculate circle area, circumference, diameter, and radius

Circle Properties

Results

Enter values and click Calculate to see results

About Circle Calculator

Circle Formulas

  • Area: A = πr²
  • Circumference: C = 2πr
  • Diameter: d = 2r
  • Radius: r = d/2

Sphere Formulas

  • Surface Area: S = 4πr²
  • Volume: V = (4/3)πr³