of a circle
is twice the radius
How to Find the Diameter from the Radius
Finding the diameter from the radius is easy.
What is the radius of the circle, with radius 5 cm, below?
the radius, 5cm, by 2.
5 × 2 = 10 cm
The diameter of the circle is 10 cm.
The slider below shows another real example of how to find the diameter of a circle from the radius.
Open the slider in a new tab
Here is an interactive widget
to help you learn about finding the diameter of a circle from its radius.
What Is a Circle?
A circle is a shape containing a set of points that are all the same distance from the center. This distance is the radius.
The diameter is the line through the center of the circle that has its endpoints on the circle.