What does Tire Size mean?

Tire size is one of the first things you should look at when shopping for a new set of wheels. There are so many sizes to choose from, and they all measure differently. The tire’s width will affect how much air it takes to fill up the tire, as well as what kind of terrain it can handle best. The height will impact your fuel economy. It might take some trial and error before you find the perfect fit for your vehicle!

Tire Size mean?(Determining Tire Size)

Tires come in different sizes for different types of vehicles. A tire’s dimensions such as height, width and diameter help determine what class of vehicles it can be used on. The names and numbers of tires may seem confusing to most people who are not familiar with them. This article will explain these measurements and terms:

Tread width

Tread width is the measurement from one side of the tire to the other at its widest point (not including any side wall bulge). If a tire is described as having a tread width of 10 inches, then you know that it is wide enough to meet standards for certain types of large trucks.

Section height

Section height refers to tall a tire is from its base to the highest point of any sidewall bulge. This measurement is often used to determine if a tire can be used on certain types of vehicles, specifically RVs, buses and some trucks.

Aspect ratio

Tire aspect ratio represents the height of the tire divided by its width. If a tires aspect ratio is 50 percent or more, then it would be considered extra-wide by most standards. Most passenger car tires have an aspect ratio between 10 and 30 percent. Extra-wide truck tires may have an aspect ratio as high as 80 percent.


Tires are measured in inches from one side of the wheel to another at their widest point (not including side wallge). The diameter is usually found on the tire and wheel that matches your vehicle. If you need to replace a tire and you know that your current one has a diameter of 26 inches, then you will need to purchase another with a diameter of 27 inches or greater.

Load index

Each tire is given a load index number which must match the weight capacity as indicated on your vehicle’s door placard. It is possible for some tires to have either higher or lower capacities than those listed on the door plate. Always follow those specifications rather than those found in any owner’s manual.

Treadwear indicator bars

Also known as wear bars, these are located at both edges of a tire’s tread grooves where they meet the sidewall surface. When the tread bars on a tire are visible, it is time to replace the tire.

Maximum tire pressure

This refers to the amount of air pressure your tires should have when they are fully loaded. The maximum tire pressure can be found in your vehicle’s owner’s manual or on a placard attached somewhere inside the vehicle. Never exceed this maximum air pressure as it could cause damage to your wheels and other components. It may also mean that you have received incorrect-sized tires for your car.

Tire identification number (TIN)

Tires have a unique serial code which contains information about their size as well as specifics about the manufacture date and place where they were made. Today, all major manufacturers use standardized codes so you cannot use a tire’s code to determine its size. The TIN is usually located on the sidewall of your tires.

Tire speed rating

Temperature grades

This is a letter designation that indicates the tire’s effectiveness at dissipating heat, which is directly linked to its rolling resistance. The grades range from A to C with A being the most effective and C meaning least effective.

Treadwear duration

This is an estimate of how long a new set of tires will last under normal driving conditions before they must be replaced. It is usually determined after on-road testing conducted by tire manufacturers on new tires that have been properly inflated and aligned.