How to read tire size on the sidewall
The numbers and letters on your tire sidewall and door jamb tell you which tires fit your vehicle and how much load and speed they are rated for. Use this guide to read them with confidence, then confirm the size printed on your own tires before you order.
The main size string (example: 265/70R17)
Most passenger and light-truck tires sold in the U.S. use a metric size format. Reading left to right: the first number is section width in millimeters (265 = about 265 mm wide). The number after the slash is aspect ratio—the sidewall height as a percent of width (70 means the sidewall is 70% as tall as the tire is wide). The letter R means radial construction (nearly all modern tires). The last number is rim diameter in inches (17 = fits a 17-inch wheel).
Some sizes add LT before the width (for example LT265/70R17). That marks a light-truck metric size, usually with higher load capacity than a same-number passenger tire. Euro-metric sizes follow the same width/aspect/R pattern but may use different load and speed markings; always match what your vehicle calls for.
Load index and speed rating (example: 115T)
After the size, you often see a load index and speed rating molded into the sidewall. The load index is a number that maps to a maximum load per tire at a set pressure—higher numbers mean more capacity. The speed rating is a letter (for example T, H, or S) that indicates the maximum speed the tire is designed to handle when properly inflated and loaded.
Your replacement tires should meet or exceed the load index and speed rating shown on your vehicle’s placard or in the owner’s manual. If you tow or haul near your vehicle’s limits, pay extra attention to load index and, on LT tires, load range (see our load range guide).
LT load range letters
Light-truck tires may show a load range letter such as C, D, E, or F instead of (or in addition to) a passenger-style load index. Those letters relate to how much load the tire can carry at a specified pressure. Heavier trucks and towing setups often need a higher load range than everyday highway use.
Do not guess: compare any replacement to the load range or load index on your door placard and on the tires you are replacing.
Where to find your size
Check three places: the sidewall of the tire currently on your vehicle (look for the full string such as 265/70R17 and the load/speed marks), the driver’s door jamb placard (often on a sticker when you open the door), and your owner’s manual.
The door placard shows the tire size the vehicle was equipped with from the factory. If you or a previous owner installed a different size, the placard may not match what is on the wheel today—always read the sidewall of the tire you plan to replace.
Shop with your size
Once you have the full size string, you can search our catalog by that size, browse common sizes, or shop by tire type (all-terrain, highway, mud-terrain, light truck, and more). If you are unsure, our team can help you confirm fitment before you place an inquiry.
Shop by size
Enter your sidewall size to see live prices on tires in local stock, or browse the size index.