How to Read a Tire Sidewall

Once you find the series of numbers on your tire’s sidewall, use the diagram above and the list below to find the meaning of each number.

  1. Metric, or tire type, defines the proper use of the tire. For example, a "P" designation means that it is a passenger car tire. An "LT" designation is for a light truck. No letter before the width indicates that it is a European metric tire.
  2. Tire width is the width of the tire measured in mm from sidewall to sidewall. This tire width is 225 mm.
  3. Aspect ratio is the ratio of the height of the tire's cross-section to its width. On our example, 60 means that the height is equal to 60% of the tire's width.
  4. Construction tells you how the layers of the tire were put together. "R" stands for radial, which means the layers run radially across the tire. "B" stands for bias construction, which means that the layers run diagonally across the tire.
  5. Rim diameter is the width in inches or cm of the wheel from one end to the other. The diameter of this wheel is 16 in. Always replace a tire on a rim with another tire of exactly the same rim diameter designation and suffix letters.
  6. Load index is an assigned number that corresponds with the load-carrying capacity of a tire. Most passenger car tire load indexes range from 75 to 100, but a few carry more. You'll also find the maximum load elsewhere on the tire sidewall, both in lbs and kg. Learn more about tire load index.
  7. Speed rating tells you the maximum service speed for a tire. A speed rating isn't, however, a recommendation to exceed speed limits, and doesn't indicate how well a tire handles or corners. Learn more about tire speed rating.

Goodyear also offers high flotation tires. You will be able to choose your tire size, tire width, and tire rim size within the tire finder tool. Don’t know your tire size, or can’t read the numbers on your sidewall? Not to worry. Our advanced Tire Finder can help. Simply filter BY VEHICLE to browse by year, make, model, and version of your vehicle.

Where to Find Your Tire Size

In addition to your tire’s sidewall, you may also find your tire size in the following places:

  1. Your driver's side door jamb
  2. Inside your glove box door
  3. Within your gas tank hatch