Surface Area of a Circle Calculator

Calculate the Area of Your Circle

Enter the radius of the circle.

Quickly determine the surface area of any circle (its area) with our user-friendly online calculator. Simply input the radius, and get instant, accurate results. Understand the fundamental area of a circle formula (A = πr²) and simplify your geometry calculations effortlessly for academic or practical needs.

Formula:

The formula to calculate the surface area of a circle (more commonly known as its area in 2D geometry) is:

A = πr²

  • A = Surface Area (Area) of the Circle
  • π (Pi) ≈ 3.1415926535 (a mathematical constant)
  • r = Radius of the Circle (distance from the center to any point on the edge)

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