tire/rim size conversion web site
 

does anyone know what the web site is that calculates the difference in total wheel diameter and speedometer changes???
i have done a search and can find out the twoo different wheel diameters but i want to know the effects on the speedometer
thank you

what car do you have and what are the two tire sizes your thinking of?

and heres one
http://www.miata.net/garage/tirecalc.html

Look in the stickies. There are a few of them there.

stock 175/70/R13 to a 195/50/R15

oh i see it sorry guys i did a search but i guess it wasn't good enough hahaha