How Do You Read Tire Size?
Tires are an essential part of driving a car, truck, or SUV and an even more critical part of keeping everyone safe in any vehicle. If you are here because you want to know how to read tire size, all the most important information is below. Even though it seems like the letters and numbers on tires are confusing, it’s actually pretty easy to figure out what tire numbers mean. Before selecting your next set, check out the tire size information below.
What do the numbers on a tire mean?
The numbers on a tire help decode some vital information, such as the tire size, the type of tire, and other features. It is essential to know what these numbers mean so you can select the correct type of tires in the future. For instance, if your tires say P205/60 R16 92H, here is the breakdown.
| Tire Size Letter/Number | Meaning |
| P | Tire class – Passenger Car or Light Truck (LT) |
| 205 | Tire width – This measurement indicates how much of your wheel is in contact with the road. |
| 60 | Aspect ratio – Tire’s sidewall height divided by its width. |
| R | Tire construction – Radial or Diagonal/Bias (D) cord plies make up the tire. |
| 16 | Wheel diameter size – How big is the rim’s diameter? |
| 92 | Load index – The amount of weight a tire can carry. Larger vehicles require a higher load index. Towing/Payload carrying vehicles require even more. |
| H | Speed rating – What is the maximum speed these tires can handle? Going too fast on tires with too low a speed rating can have catastrophic results. |
All this information should be easily accessible on the side of the tire. If your tires are worn down, and the information is no longer visible, a sticker should be inside the driver’s door to tell you the best tire fit. If you cannot read this information on the tire, it might be time to replace the set.
How do I read my car tire size?
As shown in the table above, each section contains different information. To read tire size, it is good to know what each piece means. The tire class section determines what sort of vehicle you are driving. In this example, the P in P205/60 R16 92H tells us this is a passenger car. That can be anything from cars, trucks, SUVs, or anything else under one half-ton. If it says LT, that means SUVs, pickups, and vans ¾ of a ton or larger.
The next piece of information will be the tire width, P205/60 R16 92H, measured in millimeters. This tells you how much the tire is in contact with the road. For the aspect ratio, P205/60 R16 92H tells the percentage ratio of a tire’s height to its width. The tire construction segment, P205/60 R16 92H, tells us how the cords in the tire are arranged. Mostly, this will be R. Sometimes, diagonally constructed tires will show a D.
In the area of wheel diameter or size, P205/60 R16 92H, this tells you how large the rim is. This example uses a 16″ wheel size, a rim with a 16″ diameter. The load index, P205/60 R16 92H, tells the maximum weight the tires can hold. Most vehicles fall between 75 and 100 for the load index. A 92 indicates the tires can support 1,389 pounds.
Finally, the last letter, P205/60 R16 92H, indicates the maximum speed the set of tires can hold. High-performance tires and winter tires will usually have different numbers that they can support. Most of the time, tires indicate H, S, or T. H means 130 mph, S is 112 mph, and T is 118 mph.
Does tire size matter?
If you want to know how to read tire size, you probably already know it is essential. Having the incorrect tires on can put your vehicle at risk and potentially put other cars at risk. For instance, having too small tires on a heavy truck can make braking harder. Tires that are too big probably won’t fit on the wheel correctly.
If you are looking at aftermarket options, here’s a guide on how to select the right aftermarket wheels like a pro. Buying new rims or different-sized wheels means you need new tires, so be sure to factor that into the cost. Additionally, you’ll need to get your new tires mounted and balanced. You need the correct size of wheels and tires, but there are many ways to find the right ones.
Online retailers like Tire Rack or Discount Tires allow you to put in the year, make, and model to find the right set. You can also call your local dealership for help if all else fails.
