Tire Size Calculator
 

Tire fitment guide.



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

Here is another Tire Fitment Guide that I use at work, its nice cause you can compare multiple sizes at the same time.

http://www.1010tires.com/tiresizecalculator.asp

I like that one myself Miller.....................

Another one that i used a lot when i had my subarus. Deals with both wheels and tires.

Online Wheel and Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit