Your tire size is printed on the sidewall of each tire and on a label inside your driver's door jamb

The easiest place to look is the sticker on the inside of your driver's side door, where the door latches when closed. Open the door fully and look at the edge of the door frame itself — you will see a white or silver label with vehicle information printed on it. This label lists the recommended tire size for your vehicle, along with load ratings and inflation pressure. The tire size appears as a string of numbers and letters, like 225/65R17 or P205/55R16.

If that label is missing or illegible, walk to any tire on your vehicle and look at the sidewall — the outer edge of the tire. The tire size is molded into the rubber in large text. You will see it clearly if you crouch down and look at the side of the tire facing outward. This is the actual size of the tire currently on your vehicle, which may differ from the recommended size if the tires have been changed.

Your vehicle's owner's manual also lists the correct tire size. If you have the manual, check the tire or wheels section — it will show the recommended size and any alternative sizes approved by the manufacturer.

Key Takeaways

  • The door jamb label on your driver's side shows the manufacturer's recommended tire size and is the fastest place to look.
  • The sidewall of any tire on your vehicle displays the actual size of that tire in large molded text.
  • Recommended size and actual size may differ if tires have been replaced, so check both if you are unsure.
  • Your owner's manual contains the correct tire size in the wheels or tires section.
  • Tire size format includes width, aspect ratio, construction type, and wheel diameter — for example, 225/65R17 means 225 millimeters wide, 65 percent sidewall height, radial construction, and 17-inch wheel.

Understanding the tire size format

Once you find the tire size, you need to understand what the numbers and letters mean. A typical size like 225/65R17 breaks down as follows: 225 is the tire width in millimeters, 65 is the aspect ratio (the sidewall height as a percentage of width), R means radial construction (the standard for all modern tires), and 17 is the wheel diameter in inches.

Some tire sizes begin with a letter — P225/65R17 means passenger vehicle, while LT225/75R16 means light truck. This letter tells you the vehicle class the tire is designed for. A few older vehicles use metric sizing without a letter, but this is rare on cars made after 1980.

After the wheel diameter, you may see additional numbers like 104H or 98T. These are the load index (how much weight the tire can carry) and speed rating (the maximum speed the tire is rated for). You do not need to match these exactly when replacing tires, but they should be similar to the original.

Why the door jamb label matters more than the tire sidewall

The label on your door jamb shows what the vehicle manufacturer recommends for your specific car, truck, or SUV. This is the size you should use when buying replacement tires. The sidewall shows what is currently on the vehicle, which may be correct — or may not be, if a previous owner or mechanic installed a different size.

Using a tire size different from the manufacturer's recommendation can affect your speedometer accuracy, fuel economy, and how the vehicle handles. Some tire shops will refuse to install a size that differs significantly from the recommendation without written approval from you. For this reason, always start with the door jamb label when shopping for new tires.

If you want to use a different size than recommended — for example, a larger tire for a different look — you can, but you should understand the trade-offs. Tire shops and online tire retailers can explain how a size change will affect your vehicle's performance.

Finding tire size on older vehicles or when the label is damaged

If your door jamb label is faded, peeling, or missing, the sidewall of your current tires is your next reliable source. The molded text on the tire sidewall is permanent and will not fade or wear away. Crouch down and look at the outer edge of any tire — you will see the size clearly printed there.

For vehicles older than 1980 or those with missing labels, your owner's manual is the most dependable source. If you do not have the manual, you can often find a PDF version online by searching for your vehicle's year, make, and model plus "owner's manual." Tire retailers and dealerships can also look up the correct size if you give them your vehicle's year, make, model, and VIN (vehicle identification number).

Checking tire size before you buy replacements

Before you purchase new tires, confirm the size you need by checking both the door jamb label and the sidewall of your current tires. Write down the size from the label — this is what you should order. If the sidewall size differs, ask the tire shop why before you buy. The difference might be intentional (if a previous owner upsized), or it might be an error.

When you receive your new tires, verify that the size on the box and the sidewall of the new tires match what you ordered. Tire shops sometimes make mistakes, and catching it before installation saves time and frustration.

Frequently Asked Questions

What if my door jamb label shows two different tire sizes?

Some vehicles list two approved sizes — typically a standard size and an optional larger size. Both are correct for your vehicle. Choose whichever size you prefer, but stick with one of the two listed. Do not use a size that does not appear on the label.

Can I use a tire size that is slightly different from what the label says?

Tire shops can install sizes within a certain range of the recommended size, but the closer you stay to the label, the better your vehicle will perform. Differences of one inch in wheel diameter or a few millimeters in width are sometimes acceptable, but check with a tire professional first.

Does the tire size on the sidewall change as the tire wears?

No. The size molded into the sidewall is permanent and does not change as the tire wears down. It always shows the tire's original dimensions, not its current condition.

What if I cannot find the door jamb label and do not have my owner's manual?

Call a tire shop or your vehicle's dealership with your year, make, model, and VIN. They can look up the correct size in seconds. You can also search online for your vehicle's specifications — most automotive websites list tire sizes by model year.