Circle Measurements Calculator: Area, Circumference, Diameter, and Radius

Calculate Circle Measurements

Quickly determine essential circle measurements like area, circumference, diameter, and radius with our free online calculator. Ideal for geometry students, engineers, and hobbyists needing precise circular dimensions for their projects.

Formula:

The Circle Measurements Calculator uses the following fundamental geometric formulas, where r is the radius, d is the diameter, C is the circumference, A is the area, and π (Pi) is approximately 3.14159:

  • Area (A): A = πr²
  • Circumference (C): C = 2πr or C = πd
  • Diameter (d): d = 2r
  • Radius (r): r = d/2 or r = C/(2π) or r = √(A/π)

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