Great thread!

Also, here's a trick for converting metric sizes to standard.

As mentioned, for the width you just divide the first number by 25.4. So a 265/70/17 is 265/25.4= 10.4" wide.

For the height you do the following:
First number x second number / 1270 + third number
example: 265/70/17 is
265 x 70 / 1270 + 17 = 31.6 inches tall

So: 265/70/17 = 31.6x10.4