HOW TO READ TIRE SIZING
Also called Section Width, this is the width of the tire (or thickness) in millimeters if measured from a tire's widest point of its outer sidewall to the widest point of its inner sidewall. Why millimeters? It originated in Europe, where the metric system is used.
This identifies the tire's aspect ratio, which is the relationship of the tire's sidewall height to the tire's width. In this example, the sidewall height of the tire is 80% of its width. The lower the ratio, the smaller the sidewall height, which means better cornering, but a rougher ride.
This is the tire's internal construction, which is "radial." Almost every tire on the road has radial construction, which means the cords of the carcass plies inside the tire "radiate" directly across from one side of the tire to the other. Other letters used are D, for diagonal construction, and B, for belted.
This number (in inches) indicates that the tire is designed to fit on a wheel with a 22.5‑inch diameter.