Tire sizes are measured for a few dimensions, height, width and rim size. The list of numbers printed on a tire will give the above information. For example, the number P215/70R16 means that the tire is for a passenger vehicle (P) with a width (sidewall to sidewall) of 215 millimeters, with a height of 70% of the width or 150.5 millimeters. The last set of numbers (R16) means that the tire is intended to fit a 16 inch rim. Depending on the type of vehicle, and rim size, 13 to 18 inches is typically what you will find in any tire store. After market, or special package tires can range from 22 inches and higher.