This calculator uses the radius of a circle to determine the diameter, circumference, and area of the circle. The formulas used to find these measurements are:

**Diameter**= 2 * radius

**Circumference**= 2 * radius * π

**Area**= π * r

^{2}

where

**π**is the number “pi” and is equal to approximately 3.14159.To find these measurements for a given circle, simply enter the radius of the circle below and then click the “Calculate” button.

Diameter: **8**

Circumference: **25.13274**

Area: **50.26548**