tires, how do i calculate overall diameter?

does anyone know a forumula for calculating the overall diameter of tires?


i need to know the hieght of 195/80 r15

worried they might foul on my guards under full compression with stock height suspension untill i get my raised front end in.

dont want to buy them to find out though.

693mm
15x25.4=381
195x0.8x2+381=693mm

Try this site..it's been the best tool!
http://www.tyresave.co.uk/tyresize.html

thanks guys:thumb

Or this one if a visual representation helps.

http://www.miata.net/garage/tirecalc.html