About My Tire Guide

My Tire Guide is for anyone holding a tire, or a quote for one, and wondering what the size code actually means. Each size page shows the tire drawn to scale, its height, width and sidewall in inches and millimetres, and the sizes that can replace it without upsetting the speedometer.

The measurements come from the size code itself. A metric size gives the tread width in millimetres, the sidewall as a percentage of that width and the rim diameter in inches, and from those the overall height, circumference and revolutions per mile follow. They describe the tire unloaded; a particular brand and model can differ by a few tenths of an inch.

My Tire Guide doesn't sell tires. The shop links on each size page open that store's own search for the size. To compare two sizes yourself, use the tire size calculator, or browse the tire size chart.