Tire size calculator for aftermarket wheels

Thought I would post this link up to help people with questions on wheel and tire fitment. We all run into the same problem when we get aftermarket wheels, we have to decide what width and what sidewall ratio to go with on our new tires. This is the calculator from miata. Net and it is one of the best I have seen. Put in the stock tire size 185/65/15 and then your new desired size. It will then tell you how much the new size is off (its rarely a perfect match) for instance, I use 215/45/17, which is just slightly off. Generally, within 1% is acceptable unless you wanna go with a crazy stretched or stance look. The calculator will also give you the speedo difference. For instance if your tire is .8% too large, the speedo will be off by around .5 mph


www.miata.net/garage/tirecalc.html