How to Calculate the Radius of a Circle

Calculating the radius of a circle is an important task for a variety of reasons. Whether you are constructing a circle or simply need to know the size of one, understanding how to calculate its radius is essential. In this article, we will discuss how to calculate the radius of a circle and provide a step-by-step guide that should make it easy for anyone to understand.

What Is the Radius of a Circle?

The radius of a circle is the length of the line segment from the center of the circle to any point on the circles circumference. It is the distance between the center point and the outer edge of the circle. The radius is always the same distance, regardless of where you measure it from.

How to Calculate the Radius of a Circle

To calculate the radius of a circle, you need to know the circles circumference or diameter. With those two measurements, you can apply the formula below to determine the radius of the circle.

Circumference = 2u03c0r

Or

Diameter = 2r

Where r is the radius of the circle.

Calculating the Radius from the Circumference

To calculate the radius from the circles circumference, divide the circumference by 2u03c0. The result will be the radius of the circle.

For example, if the circumference of a circle is 25.13 cm, divide that number by 2u03c0 to get the radius.

25.13 cm / 2u03c0 = 3.99 cm

Therefore, the radius of the circle is 3.99 cm.

Calculating the Radius from the Diameter

To calculate the radius from the circles diameter, divide the diameter by 2. The result will be the radius of the circle.

For example, if the diameter of a circle is 10 cm, divide that number by 2 to get the radius.

10 cm / 2 = 5 cm

Therefore, the radius of the circle is 5 cm.

Conclusion

Calculating the radius of a circle is a relatively simple task and can be done using either the circumference or diameter of the circle. To calculate the radius from the circumference, divide the circumference by 2u03c0. To calculate the radius from the diameter, divide the diameter by 2. With this information, you should now have the knowledge and skills necessary to calculate the radius of any circle