# User Friendly Circumference Of A Circle Calculator

## What Is The **Circumference Of A Circle**

Let's look at the geometric characteristics of a circle. But first, please review the definition of Perimeter Of Two-Dimensional Shapes, and Pi.

- The Perimeter Of A Circle is also known as the Circumference Of A Circle.
- The widest length is through the center of the Circle. This length is known as the diameter of the circle; In the example, it is shown as "D" in the diagram.
- If you draw a line from the exact center of the diameter to any edge of the Circle, this is called the radius; In the example, it is shown as "R". Also the radius is half the value of the diameter.
- To compute the circumference (perimeter) of a Circle, you will use Pi as part of the formula.
- Special note, the diameter of a circle must be greater than zero.

Circumference Of A Circle Formula

Formula = 2 × Pi × Radius =

Formula = 2 × π × r