Tire size calculator compares diameter, width, circumference and speedometer differences for any two tire sizes. Supports tire sizes in metric and inches.
But off hand, we all know that a 33'' can fit on an un-lifted wrangler. I would suspect that this is based on if you decide to stay with the factory wheels or locate a set with a +10 offset. We've found that a 2.5 lifted wrangler can handle 33's 34's & 35's but the rubbing will become more noticeable if the wheels have not been pushed out while increasing the tire size. Just to add, If you wrangler doesn't seem level or has a forward rake, the rubbing will be more noticeable with larger tires. I'd think about locating a wheel with the correct offset then a tire that's no wider than 11''