How to work out a circle's circumference: Easy Formula

The circumference of a circle is the measurement of the circle's perimeter - or in other words, the actual line you draw to make the circle. To work out the circumference, you will need to know the radius of the circle.

What is the radius of a circle?

The formula looks something a little like this:

2(pi)R

Now understandably, that may not mean anything to you... so, here it is in more simple terms:

Pi is the magic number used to help work out any circle's area. It is a never ending number, but for the purpose of this exercise we will take it to be of value: 3.142.

So the formula above actually means the following:

1. Multiply Pi by 2
2. Multiply the result by the radius
3. The resulting number is the circle's circumference