Hey all-
I have seen similar tire charts ect, but this one I thought helpful in that you can enter numerous tire sizes and it will list the differences in Specification, Sidewall, Radius, Diameter, Circumference, Revs/Mile,and Difference. When the page pops up there are two calculators. The top shows the difference in tire sizes, and the lower calculator at the bottom of the page will list the above specs.

Here is the link: http://www.miata.net/garage/tirecalc.html

Remember to check out the bottom part of the page for the differences in tires listed.
Thought it would be helpful.

 

That is the same one I use most of the time for checking tire sizes.

 

Very helpful. Saves me from doing it by hand like I used to.

 

Nice one. I like the one on here, too:

http://1010tires.com/TireSizeCalculator.asp

 

Very informative.