# Tire Size Calculator



## F.J.M. (Feb 21, 2010)

I didn't see anything like this here so I figured I would post it.
http://www.tacomaworld.com/forum/tirecalc.php


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## DTX (Mar 24, 2010)

Those are handy, but I think it would be usefull for people to understand a little more about how tire sizes are figured. 

The first number is the width of the tire in milimeters.
The second number is the sidewall height expressed as a percentage of the width.
The last number is, of course, the rim diameter in inches.
There are 25.4 mm in an inch

Lets take a 245/75-16

245 mm / 25.4 = 9.65 inches wide
9.65 x .75 = 7.24 inches of sidewall

so 7.24 x 2 = 14.48 inches + 16 inch rim diameter = 30.48 inches tall 

So a 245/75-16 tire would be 9.65 inches wide and 30.48 inches tall.


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## gpinjason (Nov 10, 2009)

good info... I already knew this, I was actually trying to explain it to my friend earlier today cuz he's looking for tires for his 4 door Jeep Unlimited... could have used this a few hrs ago...


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