 To calculate the perimeter of a circle from the radius, simply use our application without worrying about the formula (Perimeter = Diameter X π)

Initially, the measurement of the perimeter of a circle is calculated from the diameter and the number Pi (whose symbol is the following: π). Generally, you want to calculate the perimeter of a circle from its radius. That’s why we offer you this tool. However, if you have the diameter, you simply divide this by 2 to get its radius:

• Diameter = Radius / 2
• Radius = Diameter x 2

## Calculation Formula for Perimeter of a Circle

Thus, you can calculate the perimeter of your circle from its radius or diameter. Here are the 2 calculation formulas:

1. Perimeter = Diameter x π
2. Perimeter = (Radius x 2) x π

## Examples of the Perimeter of a Circle Calculation from the Radius or Diameter

Pi equivalent to approximately 3.14159, let us take the example of a circle having a radius of 4cm:

• Perimeter = (4 x 2) x π
• Perimeter = 8 x π
• Perimeter = 25.13

Let us reproduce the example with a circle with a diameter of 11 cm:

• Perimeter = 11 x π
• Perimeter = 34.56

Note that all dimensions are expressed in the same unit (in this example in centimeters).

Also discover our calculator to get the area of a circle.