I have been using 1010tires.com for a long time.

It is great, it tells you the

width of tires in inches

rim width range (what width rim that tire will fit)

overall diameter (the number we are all worried about i.e. height of tire)

sidewall height (how much rubber you will have)

circumference (how big your tire is around)

revs per mile (how many times your tire turns in a mile)

AND if you put in the origional tire size first it will will calculate the new tires speed compared to the origional tires 60 mile per hour speed.

Very very usefull to me, I figured yall would like it. Let me know what you think.

thats what i used to determine what size to get...great info...

_________________
Current Vehicle - 2010 Jeep Liberty - Silver
Planned mods: 245/70/16 Hankook Dynapro ATM tires, 16x7 Black Rock 950s, JK light bar with KC Daylighters
Previous Vehicles - 1988 Mustang GT, 2006 Wrangler X, 2008 KK, 2010 KK Deep Water Blue

Here is one of the better ones.
But you need Java installed.
that is free at java.com

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

THis web site i am sending you to is the greatest site in the world.
THey have done it right and all sites should follow and do it the same way.

Look at there Garage section and FAQ section. it is very impressive.

_________________
2008 Liberty Limited 4X4 Command Trac 2
All stock Auto with 235/60/18

Great place! I have been using it for quite a while also. I Highly recommend it!

_________________
07 KA Light Khaki, Manual trany.
2.5" Adjust-A-Strut JBA lift, Euro taillights,
Home made; Front Tilt Hood, Roof Rack, RAM Air, & CAI.
ESP Off Switch
Take a ride on the Trō side!