How to Find the Right Tire Size for Your Vehicle

Where to find your vehicle's tire size

Your vehicle's correct tire size is printed on a label inside the driver's side door jamb — open the door and look at the edge where it latches. The label lists tire size, recommended pressure, and load capacity. This is the most reliable place to look because it reflects what the manufacturer tested and approved for your specific vehicle.

If the door jamb label is missing or unreadable, check your vehicle's owner's manual or the sidewall of your current tires. The sidewall shows the size in a format like 225/65R17, but remember that previous owners may have installed the wrong size, so the door jamb or manual is more trustworthy.

You can also search your vehicle's information online using the VIN (Vehicle Identification Number), which appears on your registration and on the dashboard at the base of the windshield on the driver's side. Many tire retailers' websites have VIN lookup tools that will return the correct tire size for your year, make, and model.

Key Takeaways

• The door jamb label on the driver's side shows your vehicle's correct tire size and is more reliable than the sidewall of your current tires.
• Tire size appears as a code like 225/65R17, where each number and letter describes width, aspect ratio, construction type, and wheel diameter.
• Your owner's manual and your vehicle's VIN can confirm the correct size if the door jamb label is missing.
• Installing a tire size different from the manufacturer's recommendation can affect speedometer accuracy, fuel economy, and handling.
• Tire retailers can look up your vehicle's size using your VIN or by entering your year, make, and model into their website.

Understanding tire size codes

A tire size code breaks down into five parts. Using 225/65R17 as an example: 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 passenger vehicle tires), 17 is the wheel diameter in inches, and sometimes a letter at the end indicates load index and speed rating.

You do not need to memorize this code. What matters is that all five parts must match what the door jamb label specifies. If you install a tire with a different width, aspect ratio, or wheel diameter, your speedometer will read incorrectly, your fuel economy may drop, and your vehicle's handling and braking can change in ways that affect safety.

Some vehicles have multiple approved tire sizes listed on the door jamb label. This means the manufacturer tested and approved each of those sizes for your vehicle. You can choose any of them, but do not mix sizes — all four tires should be the same size.

How to use a tire retailer's lookup tool

Most tire shops and online retailers have a search tool on their website. You enter your vehicle's year, make, and model, and the tool returns a list of tire sizes that fit your vehicle. Some tools also let you filter by price, brand, or tire type (all-season, winter, performance, and so on).

If you use a VIN lookup, the tool will be even more specific because it accounts for trim level and options that affect tire size. You paste your full 17-character VIN into the search box, and the tool returns the exact size the manufacturer installed on your vehicle.

After you find your size, write it down before you leave the website. Bring this information with you when you shop, or use it to compare prices across retailers. Having the correct size in writing prevents confusion if you are shopping in person and talking to a salesperson.

What happens if you install the wrong tire size

Installing a tire size that differs from the manufacturer's recommendation creates several problems. Your speedometer will read faster or slower than your actual speed — a tire that is too small makes the speedometer read high, and a tire that is too large makes it read low. This affects not just your speed awareness but also your odometer reading and fuel economy calculations.

Handling and braking also change. A tire that is too wide or too tall can rub against the suspension or fender, especially when turning or going over bumps. A tire that is too narrow or too short may not provide the load capacity your vehicle needs, which can cause premature wear or failure.

Insurance and warranty issues can arise too. If you are in an accident and the police report shows you were using the wrong tire size, your insurance company may deny a claim. Similarly, some vehicle manufacturers will not cover suspension or drivetrain damage if you installed non-approved tires.

Tire size versus wheel size

Tire size and wheel size are different measurements, and both appear on your door jamb label. The wheel size is the diameter of the metal rim, measured in inches — the 17 in 225/65R17. The tire size is the rubber that goes around the wheel.

You cannot change the wheel size without changing the tire size, because the tire must fit the wheel. If you want to upgrade to larger wheels, you must also buy tires that fit those wheels, and the new tire-and-wheel combination must still match one of the approved sizes on your door jamb label. Many vehicles have two or three approved sizes that differ in wheel diameter, which gives you some flexibility if you want a different look.

Do not assume that a tire marked for a different wheel size will work on your vehicle. A 225/65R17 tire will not fit a 16-inch wheel, and a 225/60R18 tire will not fit a 17-inch wheel, even if the width is the same.

Where to buy tires once you know your size

Once you have your tire size, you can shop at tire retailers, auto parts stores, big-box retailers, and online sellers. Prices vary significantly, so it is worth comparing across at least three retailers. Many offer free shipping, free installation, or both if you order online and pick up in store.

When you compare prices, make sure you are looking at the same tire brand and model across retailers. A budget tire will cost less than a premium tire, but they have different tread life and performance characteristics. Some retailers offer tire warranties that cover defects or premature wear — ask about these when you compare.

Installation usually costs between $15 and $30 per tire at most retailers, though some waive the fee if you buy the tires from them. Balancing and alignment are separate services that may be recommended depending on your vehicle's condition.

Seasonal and specialty tire sizes

Winter tires, all-season tires, and performance tires all come in your vehicle's approved sizes. The tire size itself does not change — a winter tire marked 225/65R17 is the same size as an all-season tire marked 225/65R17. The difference is in the tread pattern, rubber compound, and how they perform in different conditions.

If you live in an area with winter weather, you may want to buy two sets of tires: one set of winter tires for cold months and one set of all-season or summer tires for the rest of the year. Both sets must be in your vehicle's approved size. Switching between them twice a year extends the life of both sets and improves safety.

Some people use all-season tires year-round, which is acceptable in mild climates but not recommended in areas with snow or ice. Check your local regulations — some regions require winter tires during certain months.

Frequently Asked Questions

Can I use a different tire size if it fits on my wheel?

No. Just because a tire physically fits on your wheel does not mean it is safe or legal to use. The manufacturer tested and approved specific sizes for your vehicle based on weight, suspension, and braking. Using an unapproved size can affect your speedometer, handling, braking, and insurance coverage.

What if my door jamb label is damaged or missing?

Check your owner's manual, which lists the correct tire size in the specifications section. If you do not have the manual, use your VIN to search on a tire retailer's website or call your vehicle's dealership with your VIN and they will tell you the correct size.

Do I need to replace all four tires at once?

It depends on your vehicle's drivetrain. All-wheel-drive vehicles usually require all four tires to be the same size and tread depth, or the transmission can be damaged. Front-wheel-drive and rear-wheel-drive vehicles may allow you to replace just two tires, but check your owner's manual or ask your mechanic.

What does the load index number on a tire mean?

The load index is a two-digit number that indicates how much weight the tire can safely carry. Your door jamb label specifies the correct load index for your vehicle. Do not buy a tire with a lower load index than recommended, as it may not safely support your vehicle's weight.

Can I mix tire brands or types on the same vehicle?

It is not recommended. All four tires should be the same brand and model for consistent handling and safety. If you must replace only two tires, install them on the rear axle, not the front, to reduce the risk of loss of control.