googlel the make and size of the tire. it will give you the diameter. Example I have Nitto Invo 345/25/20 on the rear, the overall inflated diameter is 26.6. I just googled the size of the tire you are looking at and it comes up with a 29.02 over inflated diameter.Wanting to put 22's on my caprice using 255/35. Was wondering what the total diameter of the wheel plus tire would be. Thanks.