Circumference of Circle

Geometry Calculators

Enter your value in one of the geometry calculators below to calculate the circumference of a circle.

Calculate the circumference with radius

Calculate the circumference with diameter

How to calculate the circumference of a circle with a radius value: Use the calculator titled "Calculate the circumference with radius". Enter a value in the radius field and click on the "Calculate circumference" button. Your answer will appear in the "circumference" field.

How to calculate the circumference of a circle with a diameter value: Use the calculator titled "Calculate the circumference with diameter". Enter a value in the diameter field and click on the "Calculate circumference" button. Your answer will appear in the "circumference" field.

Geometry Definitions

The following is a list of definitions relating to the circumference of a circle.

What is circumference?

Circumference is the linear distance around a circle.

What is a circle?

A circle is a two-dimensional shape that is created by drawing a line that is curved so that its ends meet and every point on the line is the same distance from the center.

What is the radius?

The radius is the distance from the center of the circle to any point on the outside of the circle.

What is the diameter?

The diameter is the distance of a straight line starting at any point on the outside of the circle that passes through the center of the circle to another point on the outside of the circle.

Geometry Formulas

The formula to calculate the circumference of a circle is:

C = 2 x π x r

or

C = π x d

where...

C = Circumference of circle
π = 3.141592654
d = diameter of circle
r = radius of circle

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Circumference of Circle - Geometry