Where the tire size is printed on your tire sidewall

The tire size is stamped into the rubber on the side of your tire, not on the tread. Look at the outer sidewall — the part you see when you stand next to your car — and you will find a series of numbers and letters printed in raised or recessed text. This marking is permanent and does not wear away.

The size code looks like this: P215/65R15 95H. Each part of this code tells you something different about the tire. The letter at the start (P in this example) indicates the tire type — P means passenger car. The first number (215) is the tire width in millimeters. The second number (65) is the sidewall height as a percentage of the width. The letter R means radial construction. The final number (15) is the wheel diameter in inches. The last two characters (95H) are the load index and speed rating.

Key Takeaways

  • Tire size is printed on the outer sidewall of each tire and includes width, sidewall height, construction type, wheel diameter, load index, and speed rating.
  • You can also find the recommended tire size for your vehicle on a sticker inside the driver's door jamb or in your owner's manual.
  • The load index number tells you the maximum weight each tire can safely carry; the speed rating letter tells you the maximum speed the tire is rated for.
  • If you cannot read the sidewall clearly, your vehicle's door jamb sticker or manual will show the exact size and specifications your car needs.

Reading the load index and speed rating

The last two characters on the tire sidewall are the load index and speed rating. The number is the load index — in the example above, 95 means that tire can carry a maximum of 1,521 pounds. This matters because your vehicle's total weight is distributed across all four tires, and each tire must be rated to handle its share.

The letter after the load index is the speed rating. In the example, H means the tire is rated for a maximum sustained speed of 130 miles per hour. Common speed ratings range from L (75 mph) to Y (186 mph). Your vehicle's door jamb sticker will tell you what load index and speed rating your car requires, and you should never install a tire with a lower rating than what is specified.

Finding the tire size on your vehicle's door jamb

You do not have to look at the tire itself to find the size. Open your driver's side door and look at the inside edge of the door frame — there is a white or silver sticker permanently attached there. This sticker lists the tire size your vehicle manufacturer recommends, along with the correct air pressure for your front and rear tires.

The door jamb sticker is easier to read than the tire sidewall, especially if your tires are dirty or the sidewall text has faded. The sticker shows the size in the same format as the sidewall (for example, P215/65R15 95H), and it also lists the load index and speed rating your vehicle needs. If you are buying replacement tires, this sticker is the reference you should use.

Checking your owner's manual for tire specifications

Your vehicle's owner's manual contains a section on tire and wheel information, usually near the front or in the maintenance section. This manual will list the original tire size, the load index, the speed rating, and the correct tire pressure for normal driving and for highway speeds.

The manual is useful if the door jamb sticker has been removed or is no longer readable. It also explains what the numbers and letters mean, and it may list alternative tire sizes that are acceptable for your vehicle. If you have lost your manual, you can usually find a PDF version on the vehicle manufacturer's website by entering your vehicle's year, make, and model.

Understanding tire size variations and what they mean

Not all tires with the same width and diameter are identical. Two tires might both be labeled 215/65R15, but one could have a load index of 95 and another could have 98. The higher number means that tire can carry more weight. Similarly, one tire might be rated H (130 mph) and another might be rated V (149 mph).

When you replace a tire, you can choose a tire with a higher load index or speed rating than the original, but you should not go lower. Installing a tire with a lower load index or speed rating than what your vehicle requires can cause the tire to overheat, wear unevenly, or fail under normal driving conditions. Your door jamb sticker shows the minimum specifications your vehicle needs.

What to do if the sidewall text is worn or illegible

If your tire sidewall is too dirty or worn to read, clean it first with a brush and water. Dried mud and brake dust often obscure the text. If the text is still not visible after cleaning, the tire is old enough that the sidewall may be degraded, and you should consider replacing it regardless of tread depth.

In this situation, use your door jamb sticker or owner's manual as your reference instead. You do not need to read the sidewall of an existing tire to know what size to buy — your vehicle's specifications tell you exactly what you need. If you are unsure whether a tire meets your vehicle's requirements, a tire shop can verify the specifications for you before you purchase.

Frequently Asked Questions

Can I use a different tire size than what is on my door jamb sticker?

You can use a slightly different size in some cases, but only if the load index and speed rating meet or exceed what your vehicle requires. The tire diameter should not vary by more than 3 percent from the original size, or your speedometer and odometer will be inaccurate. A tire shop can tell you which alternative sizes are safe for your vehicle.

What does the P at the beginning of the tire size mean?

The P indicates a passenger car tire, as opposed to a light truck (LT) or temporary spare (T) tire. Most cars use P-rated tires. Light trucks and SUVs often use LT tires, which have different load ratings. You should match the tire type to what your vehicle requires.

Why does the door jamb sticker show two different tire pressures?

The sticker lists a pressure for normal driving and a higher pressure for highway or heavy-load driving. Use the lower pressure for everyday driving unless you are carrying a full load of passengers or cargo. Check your tire pressure when the tires are cold — before you have driven the vehicle or at least three hours after driving.

Is the speed rating important if I never drive fast?

Speed rating matters for tire safety even if you do not drive at high speeds. A tire rated for a lower speed is built with different materials and construction, and it may overheat or fail under normal driving conditions if it is not rated for your vehicle's top speed. Always match or exceed the speed rating on your door jamb sticker.