What Do the Numbers on My Tires Mean? 

When you look at your vehicle’s tires, you’ll see a series of numbers and letters printed on the sidewall. While they might initially seem confusing, these numbers carry significant information about your tire’s specifications. Here’s a guide to understanding what each section of this code means.

Where Can I Find My Tire Numbers?

These numbers, commonly called the tire code, are prominently displayed on the tire’s sidewall. If you’re ever in doubt, consult your vehicle’s owner manual or check the driver’s side door jamb for the recommended tire specifications. 

Breaking Down the Tire Code: P215/65 R15 95H for example 

  • Tire Type: The first letter, such as ‘P’ in our example, indicates the type of vehicle the tire is designed for. 
    • P: For passenger vehicles – ideal for cars, SUVs, and smaller trucks that generally don’t drive off-road. 
    • LT: Suitable for light trucks or SUVs that carry heavy loads or travel on rough terrains. 
    • ST: Specialized for trailers, including campers and boat trailers. They’re not meant for regular vehicle wheels. 
    • T: Temporary or spare tires for temporary use. 
    • No letter? It might be a Euro-metric tire. Consult a technician to confirm compatibility. 
  • Tire Width: The next three numbers, e.g., ‘215’, denote the tire’s width in millimeters from one sidewall to the other. 
  • Tire Aspect Ratio: This number is a percentage signifying the tire’s height compared to its width. In our example, ’65’ indicates the tire’s height is 65% of its width. 
  • Tire Construction Type: 
    • R: Radial construction, where layers run radially across the tire 
    • D: Diagonal or bias ply construction with a crosshatch pattern 
    • B: Belted bias, which is reinforced with a sturdy material belt 
  • Wheel Diameter: Following the construction type, you’ll see a number, ’15’ in our example, representing the diameter of the wheel rim in inches the tire is designed to fit. 
  • Load Index: This indicates how much weight the tire can safely bear. In our example, ’95’ means the tire can support up to 1,521 pounds. The index ranges between 0 and 150, with most passenger vehicles using tires between 75 and 100. 
  • Speed Rating: The last letter indicates the tire’s maximum speed capability. ‘H’ in our sample means the tire can achieve speeds up to 130 mph. Some ratings come with a letter and number, such as A1-A8, which are designed for slower speeds.

Why is Understanding Tire Numbers Essential?

Knowing what each section of your tire’s code represents, you can make informed decisions about tire replacements and understand their limitations. It also ensures that when purchasing new tires, primarily online, you choose the right fit for your vehicle’s needs and driving habits.


While the numbers and letters on your tire’s sidewall may seem perplexing at first, they are essential for understanding your tire’s specifications. Familiarizing yourself with this code ensures you make the right choices for your vehicle’s safety and performance. Consider seeking expert advice or consulting your vehicle’s manual if ever in doubt.

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