How to Read Tire Sidewall Markings

A tire sidewall is more than a place for a brand name. Its molded letters and numbers describe the tire’s size, construction, operating limits and identification details. Knowing how to read them can make it easier to understand the tire already on a vehicle and to have a clearer conversation when it is time to discuss replacement options.

Sidewall markings are standardized enough to be useful, but they are not a shortcut for choosing any tire that looks similar. The correct replacement still needs to suit the vehicle, wheel and intended use. Think of this guide as a way to decode the label—not as a substitute for vehicle-specific fitment guidance.

Start with the tire size

A common passenger-tire size looks like P215/60R16 95H. The letters and numbers appear together, but each part answers a different question. In this example, P identifies the tire type, 215 is its width, 60 is its aspect ratio, R describes the construction, 16 is the wheel diameter, and 95H combines the load index and speed rating.

Not every tire begins with a P. Some use LT for light-truck applications, and some size formats omit a leading letter. The important point is to read the complete marking as a specification rather than focusing on one number in isolation.

Section width: 215

The first three-digit number is the tire’s nominal section width in millimeters. In the example, 215 means the tire is about 215 millimeters wide at its widest point when mounted on the appropriate measuring rim. It is not a promise of the exact amount of tread on the road, and it does not by itself tell you whether a tire will fit a particular vehicle.

Aspect ratio: 60

The number after the slash is the aspect ratio. It expresses sidewall height as a percentage of the section width. A 60-series tire has a sidewall height equal to 60 percent of its nominal width. Because it is a ratio, the same aspect-ratio number can represent a different physical sidewall height on a wider or narrower tire.

This relationship helps explain why tire sizes that seem close can still change overall diameter, ride characteristics or clearance. Width and aspect ratio belong together.

Construction: R

The letter R means radial construction, the common construction type on modern passenger vehicles and many light trucks. You may encounter other letters on specialized or older fitments, but R is the marking most drivers see. Construction is part of the tire’s design and should not be ignored when comparing specifications.

Wheel diameter: 16

The final number in the size portion is the wheel diameter in inches. In this case, the tire is designed for a 16-inch wheel. This number must match the wheel diameter; a tire marked for a 16-inch wheel cannot be mounted on a 17-inch wheel, even if other numbers appear similar.

Understand the load index and speed rating

After the size, many tires show a number followed by a letter. In 95H, the 95 is the load index and H is the speed rating. These codes are useful because two tires with the same physical size can have different operating capabilities.

Load index

The load index is a code that corresponds to a maximum load capacity for one tire when used under specified conditions. It is not a weight measured directly in pounds on the sidewall; a load-index table translates the code. Because a vehicle’s carrying requirements involve all four tires and the vehicle manufacturer’s specifications, it is best not to assume that a higher or lower number is automatically suitable.

When comparing replacements, keep the complete tire specification in view. Load capacity is particularly important for vehicles that carry passengers, cargo or equipment, but it matters for every vehicle.

Speed rating

The letter after the load index is the speed rating. It indicates a tire’s tested speed capability under controlled conditions. It is not a recommendation to drive at that speed, and it never overrides speed limits, road conditions or safe driving judgment. It is simply one part of the tire’s performance specification.

Speed ratings can also be connected to handling, heat resistance and other design choices. That is why matching the vehicle manufacturer’s recommendations matters more than selecting a letter based on its position in the alphabet.

Find the DOT tire identification number

Look for the letters DOT followed by a series of characters. This is the U.S. Department of Transportation tire identification number. It identifies manufacturing and other tire information. The complete sequence may appear on one sidewall, while the date portion is typically found at the end of the code on one side of the tire.

The final four digits show the week and year of manufacture. For example, 2324 means the tire was made in the 23rd week of 2024. This code is helpful when reviewing a tire’s age, but it should not be the only factor used to judge condition. Storage history, visible damage, tread wear, pressure maintenance and professional inspection all matter.

Other markings you may see

Sidewalls can carry many additional labels. Some identify the manufacturer or model. Others describe seasonal use, traction and temperature grades, maximum inflation pressure, maximum load, or whether the tire is tubeless. A tire may also be marked M+S or display a winter-related symbol, depending on its design and certification.

These details are useful for comparing like-for-like products, but wording can vary by tire type. For instance, “maximum inflation pressure” is a tire limit, not necessarily the pressure that should be used on a specific vehicle. For routine inflation, follow the vehicle’s recommended cold tire pressure information rather than treating the tire-sidewall maximum as the everyday target.

Why matching the full specification matters

It is tempting to compare only the width and wheel diameter, such as 215 and 16. That misses important differences in aspect ratio, load index, speed rating and construction. A replacement tire should also be appropriate for the wheel, the vehicle and how it is used. Changes to tire dimensions can affect speedometer readings, clearance and vehicle behavior, so they deserve careful consideration.

If the markings are worn, difficult to read or confusing, write down what is visible and check the vehicle documentation. A tire professional can help confirm which specifications apply before installation. Rapid Tire and Auto provides tire-related services in Phenix City, including tire installation, repair, rotation and balancing; contact the shop to discuss your vehicle’s current tire needs.

A simple sidewall-reading checklist

• Read the entire size, not just the first three-digit width number.
• Confirm the wheel-diameter number matches the wheel.
• Note the load index and speed rating when comparing similar sizes.
• Locate the DOT code and, when available, read its final four-digit date portion.
• Use the vehicle’s recommended tire information for fitment and routine pressure guidance.
• Ask for help if there is damage, unusual wear or uncertainty about a replacement.

Frequently asked questions

What does 215/60R16 mean on a tire?

It describes a tire with a nominal 215-millimeter width, a sidewall height equal to 60 percent of that width, radial construction and a 16-inch wheel diameter.

Is the maximum pressure on the tire the pressure I should use?

No. The sidewall maximum is a tire limit. Use the vehicle manufacturer’s recommended cold tire pressure for normal operation unless qualified guidance for the vehicle says otherwise.

How do I tell how old a tire is?

Find the DOT tire identification number and look for its final four digits. The first two are the production week and the last two are the production year. Tire age alone does not establish condition.

Can I replace a tire with one that has a similar-looking size?

Similar-looking markings can hide important differences. Compare the complete specification and confirm fitment for the vehicle and wheel before selecting a replacement.