Use this circle calculator to find the area, circumference, radius or diameter of a circle. Given any one variable A, C, r or d of a circle you can calculate the other three unknowns.
The radius of a circle is the distance from the center of the circle to any point on its circumference. The easiest way to find the radius is by dividing the diameter in half.
What is the radius of a circle – learn how to find it with equation, and solved examples