Lawn tractor tires come in many different sizes that accommodate the all the various different types of lawn tractors on the market. Like other tires, the information for the lawn tractor tires are written on the side of the tires. The information is usually displayed as a series of numbers and letters. Once you begin to understand what all these numbers and letters mean, you'll be able to read a lawn tractor tire size--and replace the tire correctly when the time is needed.
Look at the sidewall of your lawn tractor tire. There should be a series of numbers or numbers and letters on it. If you don't see anything, try washing the tire to make them appear.
Count the numbers and determine the size from the numbers. The number sequence has either two or three numbers. In two-number sequences, the first number of the sequence is the width in inches, and the second number will be the diameter of the rim in inches. If the sidewall of the tire reads "12.4-26", that means the width of the tire is 12.4 inches and the diameter of the rim is 26 inches.
Determine the size if there are three numbers. For three-number systems, the first number is the height, the second is the width, and the last number is the rim size. So for a tire that reads "16/8.0-6," the height is 16 inches, the width is 8 inches, and the rim size is 6 inches.