View Here : Tire Number Meaning
Without getting too technical, this is basically the width of the tire. The next number is the sidewall aspect ratio. It represents the height of the tire — the distance between the outer edge of the wheel and the tread of the tire. This distance is measured as a percentage of the section width.
Radial tires represent 98% of the world tire market and are the most popular tire sold. 3rd Number = Tire and Wheel Diameter The next number will indicate the tire and wheel sizes. These numbers represent inches and the corresponding wheels or rims are typically sold from 16in to 36in (sometimes more).