# What is the formula for the circumference C of a circle of radius r?

The circumference of a circle is the length of the boundary of the circle.

## Answer: The formula to find the circumference C of a circle of radius r is C = 2 π r.

Let us see the formula for the circumference C of a circle of radius r.

**Explanation:**

The circumference of a circle is given by multiplying 2π with its radius.

So, the formula to find the circumference of a circle C is C = 2 π r, where r is the radius.

Let us find the circumference of a circle with a radius of 7 units.

C = 2 π r

= 2 π × 7 units

= 14 π units

You can use the Circumference of Circle Calculator to find the circumference of a circle.