Circle Calculator

Calculate circle area, circumference, and diameter from the radius or other parameters.

A = \pi r^2, \quad C = 2\pi r, \quad d = 2r

Result

Step-by-Step Calculation & Explanation

A circle is all points in a plane at a given distance (radius) from a center. The area represents the two-dimensional region enclosed by the circle, while the circumference is the boundary length.