Tire sizing for ATVs (all-terrain vehicles) can be a confusing bunch of numbers until they are explained. Once you understand how it works, it's easy to know with a glance what they mean.
ATV tires are large lugged tires with soft off-road compounds. They are designed to work in various rugged terrains and come in a variety of sizes depending on their application.
By the Numbers
ATV tire sizes are listed in general like this: 20x11x9. No matter what the numbers are, they are always listed in the same way. Only the numbers change.
The First Number
As confusing as 20x11x9 might seem, it's really not. The first number (20) is the outside diameter, or "ride height," measured in inches. It is simply how tall the tire is from the ground to the top. This number can range in most cases from 18 to 27 inches.
The Second Number
Sticking with 20x11x9 as an example, the second number is related to the width or "foot-print" of the tire. In this case, 11 means the tire measures 11 inches from side to side.
The Third Number
The third and final number stands for the rim size. This is essentially the diameter of the "hole" in the center of the tire. A 20x11x9 number means the tire is designed for a 9-inch rim or wheel.
When you put it all together, a 20x11x9 ATV tire is 20 inches tall, 11 inches wide and mounts on a 9-inch rim.