I dave a set of H2s with 315/70 R17 BFG AT KOs on my truck currently. All of the tire size calculators I've tried tell me they should be 34.4" tall, however mine measure out to 33". I've measured them vertically and horizontally and get the same number. There is a chance I'm not running enought air in them so I'll check that tonight. Can any of you who are running these tell me what diameter yours are?
Thanks.

I think that is normal. When the calculators give you the tire size that is without load. The weight of your truck will make it go down some.

sounds about right, mine measure 33.5" on the truck with 45-48 psi.

best way is to go to their site

http://www.bfgoodrichtires.com/specs/all-terrain-t-a-ko/44.html

they're 34.5"

now to accurately measure them, jack the truck up and put a string around the tire in the center of tread. measure in inches and divide by 3.1416 this will give the diameter.