Diameter of a Circle Calculator

Calculate the diameter of a circle based on the circle radius, area of a circle, or circumference of a circle in chosen units.

Method:

Circle Radius (r):

Area of a Circle (A):

Circumference of a Circle (C):

Result:

Diameter of a Circle (d):

How to use this calculator?

Select whether you want to calculate the diameter of a circle based on its radius, area, or circumference.
Enter the radius, area, or circumference, depending on what you selected in the field above.
Get your Diameter of a Circle.

There are several methods to calculate the Diameter of a Circle. Choose the one that allows you to perform calculations based on the data you have.

Multiply the Circle Radius by 2.

Diameter of a Circle = 2 * Circle Radius

Divide Circumference of a Circle by Pi (approximately 3.14).

Diameter of a Circle = Circumference of a Circle / π

Multiply 2 by the square root of the Area of a Circle divided by Pi (approximately 3.14).

Diameter of a Circle = 2 * √(Area of a Circle / π)