i hope this helps! 225/85R 14 = 29 X 9.00 X 14 215/75R 15 = 28 X 8.50 X 15 215/85R 15 = 29 X 8.50 X 15 225/75R 15 = 28 X 9 X 15 235/75R 15 = 29 X 9 X 15 325/60R 15 = 31 X 12.50 X 15 Q78-15 = 35.50 X 11.00 X 15 215/70R 16 = 28 X 8.50 X 16 225/70R 16 = 28.50 X 9 X 16 225/75R 16 = 30 X 9 X 16 235/70R 16 = 29 X 9.50 X 16 235/85R 16 = 32 X 9.50 X 16 245/70R 16 = 30 X 10 X 16 245/75R 16 = 31 X 10 X 16 255/70R 16 = 30 X 10.50 X 16 255/85R 16 = 33 X 10.50 X 16 265/70R 16 = 31 X 10.50 X 16 265/75R 16 = 32 X 10.50 X 16 265/80R 16 = 32.50 X 10.00 X 16 275/70R 16 = 31.50 X 11 X 16 285/75R 16 = 33 X 11.50 X 16 295/75R 16 = 33.50 X 12 X 16 305/70R 16 = 33 X 12.50 X 16 305/85R 16 = 36 X 11.50 X 16 315/75R 16 = 35 X 12.50 X 16 325/70R 16 = 34 X 13 X 16 325/80R 16 = 37 X 13 X 16 365/65R 16 = 35 X 14.50 X 16 Q78-16 = 35.50 X 11.00 X 16 265/70R 17 = 32 X 11.50 X 17 275/70R 17 = 32.50 X 11.00 X 17 285/70R 17 = 33 X 11.50 X 17 295/70R 17 = 33 X 12.0 X 17 305/70R 17 = 34 X 12.00 X 17 315/70R 17 = 34.50 X 12 X 17 255/55R 18 = 29 X 10.50 X 18 285/60R 18 = 32 X 11 X 18 285/65R 18 = 33 X 11.50 X 18 325/60R 18 = 33 X 13 X 18 325/65R 18 = 35 X 13 X 18 355/65R 18 = 37 X 14 X 18 305/50R 20 = 32 X 12.50 X 20 305/55R 20 = 33 X 12.50 X 20 325/60R 20 = 35 X 13.00 X 20 355/60R20 = 36.50 X 14.00 X 20 325/50R22 = 35 X 13.00 X 22

Good info. Or if you want to convert it yourself: 1. take the first number (the width in millimeters) and divide by 25.4, this give you the width in inches 2. multiply be the second number (aspect ratio) divide by 100 (percentage), this gives you the sidewall height 3. multiply by 2, the add the 3rd number (wheel diameter) Example: 275/60 R20 (factory 20" Ram tires) 1. 275/25.4= 10.82677 inches 2. 10.82677*60/100 or 10.82677/.6 = 6.496 inches 3. 6.496*2 = 12.992 + 20 = 32.992 = 33" tire height.

That chart and formula will get you in the ballpark, but depending on the manufacturer the actual tire height will vary because of tread pattern or what have you. Case in point: 265-70-17 AT tires: Formula Height: 31.61 Nitto Terra Grappler actual height: 31.57 BFG AT: 31.8 Dick Cepek Radial F-C II: 31.7 Not that a 10th of an inch makes that much real world difference, but just pointing that out.

I personally like the one in the link below as it breaks down by rim and then overall tire diameter. Tire Size Conversion Chart It makes it easy to find alternate tire size that would fit your application as well as includes metric conversions. Sort of an All-in-one tool. Hope this helps