Hey,

I was looking through the reference section and Randy's threads' link is dead. I have come across some other online tools that seem to work pretty well.

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

http://www.rimsntires.com/specs.jsp

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

This one is the best as you set for tire stretch...

http://www.jonathanrowny.com/page/offset-calculator


Post any other ones, we can get a good list and then put this in the reference section.

Cheers
Bryan