BOSSV said:
Sorry if this is a dumb question but what would that translate to for a tire size ?
It does but it doesn't, really. The only measurement that's consistent is the rim size on the tire's size code. The height is entirely dependent on ALL THREE numbers. The rim size sets the base, the second digit adjusts the height, but the first digit can also have a say in overall height. For example, a P245/75R17 tire is 31.47 inches tall. A P265/75R17 is 32.65 inches.
I highly suggest using our sister site's tire calculator, found here:
http://www.offroadtb.com/articles/tech-docs/tire-size-calculator/ You can set the rim, then play with the first two numbers to find one that fits the bill you're looking for if you don't want to use spacers. A P235/45R22? Or maybe a P265/40R22?
When it comes down to it, it's all about how the actual measurement, as installed, comes up. This would be taking a good old fashioned rule or tape measure and physically measuring across the widest part. But the tire calculator should be good enough to figure it out.