245/30/20 = 25.8 inches tall
235/25/17 = 25.3 inches tall

now there is some math for a 5th grader

 

245 x .30 = 73.5mm
235 x .45= 105.75mm
105.75-73.5 = 32.25
32.5 x 2(two sides of the tire) = 64.5mm
64.5mm = 2.5 inches
2.5 - 3(20-17) = -.5

so the 17 would be 1/2 inch smaller

 

ok you can do all the math in the world but his Pic doesnt Lie.

 

im not going to argue with that

 

Your the one who tried to explain this with your wonderful math skills so I figured I'd just set you strait. and MCHammered hasn't come back yet to tell us how much the difference actually is. It looks damn close to a 1/2 inch to me. he's really close to it so it looks to be more than it actually is. we'll just have to wait for him

 

quite simple realy
245/30/20 vs 235/45/17
30mmthickness of tyre wall /20"wheel v 45 height of tyre of tyre wall/17" wheeland the width is 10mm wider 245 v 235[:-]

 

wow - you don't even know how to read a tire size?

It the ******* aspect ratio not the dam size
This number refers to the height of the sidewall, or the Aspect Ratio. It is a percentage of the section width. In this example, you would take 45 percent of 235 millimeters and this would give you the sidewall height.

Time to go back to school

 

dont be insulting now because I know more than you think I was just putting a red herring in the post

 

I was hoping

 

http://www.offroaders.com/info/tech-...ing/wheels.htm