How to calculate length of wire needed for a ring

[ShinyLauren]

I've had a look at some charts showing the length of sheet you need to use to make a certain size ring, but I need to calculate the length of 2mm round wire and not sure how to do this.

My friend is coming round later to discuss wedding ring options. From previous discussions, I think she wants a 2mm round wire halo ring. It'll be from 18ct gold, so I want to be pretty damn accurate about the length of wire I'll need and how much it will cost.

Can anyone assist?

Thanks

[josef1]

find out you ring size diameter for example 20mm then add 2mm (1mm either side for the middle of the wire) then multipy that by 3.14 (pi)

so our example would be 22mm x 3.14 = 69.1

This is an exact length so you wouls need a bit more on the ends to bend etc

[ShinyLauren]

That's great - thanks Josef! I hadn't thought about using the diameter.