What is First Number in Tire Size? Complete Engineering Guide

What is First Number in Tire Size? Complete Engineering Guide

The first number in a tire size indicates the nominal section width of the tire measured in millimeters. When you look at a tire branded with the sequence 225/45R17, the number 225 means the tire measures exactly 225 millimeters from its inner sidewall to its outer sidewall at the widest point. Key Facts / At […]