Are you ready to learn how to find the circumference of a circle? This free step-by-step guide explores what is the circumference of a circle and how to find the circumference of a circle using the circumference of a circle formula. Together we will work through several examples, including how to find circumference of a circle with diameter given and with radius given. Use this free circumference calculator to find the area, circumference and diameter of a circle. Circumference of Circle Formula The circumference of a circle is equal to the length of its boundary, but the circle is a curved shape, its circumference can't be measured with a ruler. Another way to calculate the circumference of a circle is by using the formula: Circumference = π × Diameter. If we need to calculate the radius or diameter, when the circumference of a circle is given, we use the formula: Radius = Circumference/2π
