TIRE INFORMATION

How to Read Tire Sidewall Markings

A tire sidewall carries a compact set of markings that can look like a code at first glance. Those letters and numbers describe characteristics of the tire itself: its size format, construction, load information, speed symbol, identification code, and more. Learning the basic order helps you take accurate notes and ask better questions when comparing replacement tires.

The sidewall is useful, but it is not the only reference that matters. A tire may have been installed by a previous owner or changed after the vehicle left the factory. For vehicle-specific size and cold-inflation guidance, start with the vehicle tire-information placard and owner’s manual. The sidewall helps you identify what is mounted; it does not by itself authorize a substitution. If you have not already collected those references, begin with this guide to verifying tire specifications before shopping.

Find the complete marking before interpreting it

Look on the outer sidewall for a sequence that resembles P215/60R16 94H. This is an example, not a recommendation for any vehicle. Copy the whole sequence or take a clear photo rather than relying on one familiar-looking number. The three-digit width, the wheel diameter, the load index, and the speed symbol each have a different purpose. Leaving out one part can turn an otherwise useful note into an incomplete comparison.

Sidewalls also contain the tire brand and model, warning statements, maximum-load and maximum-inflation information, and a Department of Transportation identification code. The layout varies among tires, so the markings may not appear in exactly the same place or order on every sidewall. Use the information printed on the tire rather than trying to match a photograph online.

Read the size from left to right

In the example P215/60R16, the first letter can describe a tire classification. A P commonly indicates a passenger tire. Some tires have no leading letter, and other prefixes may be used for different service descriptions. A prefix is one reason the full marking is more useful than a partial number. It should be recorded exactly, including any letters.

The next number, 215, is the nominal section width in millimeters. It is not a guarantee of the exact width after mounting, and it does not tell you whether the tire is appropriate for a particular wheel or vehicle. It simply identifies one part of the tire’s size designation.

After the slash, 60 is the aspect ratio. It expresses the sidewall height as a percentage of the nominal section width. A smaller aspect-ratio number generally describes a shorter sidewall relative to the width, while a larger number describes a taller one. It is a ratio, not a direct height measured in millimeters. Comparing only the 215 and ignoring the 60 would miss a material part of the size.

Understand construction and wheel diameter

The letter after the aspect ratio identifies the tire’s construction. R commonly means radial construction, which is widely used on passenger and light-truck tires. Other letters can appear on particular tires, so the marking should be copied rather than assumed. Construction is part of the tire description; it is not a decorative letter.

The final number in this portion, 16, is the wheel diameter in inches for the tire in this example. It tells you the wheel-diameter category associated with that tire, but it is not enough information to choose a tire by itself. Tires that share a wheel diameter can still differ in width, aspect ratio, construction, load capability, and other markings.

It is especially easy to focus on the wheel-diameter number because it is short and familiar. Avoid treating it as a complete tire size. Record the entire sequence from the prefix through the diameter, then compare it with the vehicle placard and owner’s manual. If the vehicle has custom wheels or other changes, bring that information to a fitment discussion rather than making an assumption from the sidewall.

Locate the load index and speed symbol

Following the size, many tires show a number and a letter, such as 94H. The number is the load index. It corresponds to a load-capacity value in a standardized index; it is not a tire pressure and should not be read as a weight in pounds. The letter is the speed symbol, which corresponds to a tested speed category under standardized conditions. It is not a suggestion to drive at that speed or a statement about the safe speed of a specific vehicle, road, weather condition, or driver.

Load index and speed symbol need to be considered alongside the complete vehicle specification. A tire that shares a width and diameter with another tire can still differ in these markings. For that reason, write down the number and letter after the size rather than stopping at the wheel diameter. The vehicle documentation and qualified professional guidance are appropriate sources for confirming what applies to a particular vehicle.

Do not confuse maximum inflation with the vehicle recommendation

Near the sidewall markings, you may see statements about maximum load and maximum inflation pressure. These describe limits associated with the tire under stated conditions. They are not automatically the everyday cold-inflation target for the vehicle. For routine pressure guidance, use the cold pressure shown on the vehicle tire-information placard or in the owner’s manual.

This distinction matters because a vehicle is a system. Its recommended pressure is tied to its specifications and intended use. The number on the tire sidewall can be important to identify, but it does not replace the manufacturer’s vehicle guidance. If you are preparing notes, photograph both the sidewall statement and the placard so the information is not mixed together later.

Recognize the DOT tire identification code

A tire sidewall also includes a DOT marking followed by an identification code. The final four digits of the code indicate the week and year of manufacture: the first two digits are the week, and the last two are the year. For example, a code ending in 2324 identifies the 23rd week of 2024. The full DOT code may be printed on only one sidewall, so it can be necessary to look at the inner side of the tire as well.

The date code is useful context when documenting tires, but it is not a stand-alone condition assessment. Tire condition can involve wear, damage, repairs, storage history, pressure history, and other factors that are not answered by a date code alone. If you notice visible damage, repeated pressure loss, a bulge, or unusual wear, avoid trying to diagnose the cause from the code or appearance alone.

Make a sidewall note that is easy to use

A short, organized record is more useful than memorizing every code. Take photos in good light and make one note for each tire position if the markings differ. Include the full tire size, load index, speed symbol, brand and model if visible, and any condition concern you observe. Add a photo of the placard and a note about relevant changes such as custom wheels.

• Copy the full size sequence, including letters and punctuation.
• Record the load index and speed symbol that follow the size.
• Photograph maximum-load and maximum-inflation statements without treating them as vehicle pressure guidance.
• Note the DOT code if it is visible and accessible.
• Compare the record with the vehicle placard and owner’s manual instead of guessing from one tire.

This information can make a conversation more efficient without promising that a particular tire is available or suitable. After you have assembled it, visit the tire information page for Visalia Tire & Wheel’s published tire categories. For current fitment, availability, or service details, use the contact page.

FAQ: tire sidewall markings

What do the numbers on a tire sidewall mean?

The main size sequence identifies the tire’s size format, including nominal width, aspect ratio, construction, and wheel diameter. A number and letter after that sequence commonly identify the load index and speed symbol. Copy the complete marking because each part has a different meaning.

Is the tire sidewall the best place to find my vehicle’s recommended tire size?

The sidewall tells you what is mounted on the tire. For the vehicle manufacturer’s reference information, use the tire-information placard and owner’s manual. The two sources should be considered together before a replacement decision.

Does the maximum PSI on the tire tell me what pressure to use?

No. The maximum-inflation statement on the tire is not automatically the vehicle’s everyday cold-pressure recommendation. Use the cold pressure shown on the vehicle placard or in the owner’s manual.

What does the four-digit DOT date code show?

The final four digits show the week and year of manufacture. For example, 2324 means the 23rd week of 2024. It provides documentation context but does not, by itself, determine tire condition or serviceability.

What if the sidewall markings are hard to read or do not match across the vehicle?

Take clear photos of each tire and the vehicle placard, then ask a qualified tire professional to help verify the information. Do not resolve differences by choosing a partial match or by guessing from appearance.