The DOT code on your tire's sidewall tells you when it was made
Every tire sold in the United States has a Department of Transportation (DOT) code stamped into the rubber on the sidewall. The last four digits of this code are the manufacturing date. The first two digits are the week of the year (01 through 53), and the last two digits are the year. A code ending in 3519 means the tire was made in the 35th week of 2019.
You do not need any tools to read this code — just locate the sidewall marking and look at the numbers. The code appears as a long string of characters, and the manufacturing date is always the final four digits. This is the most reliable way to know a tire's age, since the date reflects when the tire left the factory, not when it was installed on your vehicle.
Tire age matters because rubber degrades over time, even if the tread looks fine. Most tire manufacturers recommend replacing tires ten years after manufacture, regardless of tread depth. Some insurance companies and vehicle manufacturers suggest replacement at six years. Knowing the exact manufacturing year helps you track when replacement becomes necessary.
Key Takeaways
- The DOT code on the tire sidewall ends with four digits that show the manufacturing week and year.
- The first two of those four digits are the week (01–53), and the last two are the year (so 3519 means week 35 of 2019).
- Tire age is measured from the manufacturing date, not from when the tire was installed on your vehicle.
- Most manufacturers recommend replacing tires at ten years old, though some sources suggest six years as a safer threshold.
Where to find the DOT code on your tire
The DOT code is printed on the sidewall of the tire — the curved rubber surface between the tread and the wheel rim. On most vehicles, you can see it without removing the tire. Walk around your car and look at the side of each tire facing outward. The code is a series of letters and numbers, typically 8 to 13 characters long, and it starts with the letters "DOT".
The code may be on either the inner or outer sidewall. If you cannot see it on the outside of the tire, check the inside wall (the side facing the vehicle body). You may need to crouch down or use a flashlight to read it clearly. The manufacturing date — those final four digits — will be the last numbers in the entire DOT code string.
If your tires are very old or heavily worn, the code may be harder to read because the rubber has degraded or dirt has accumulated. Wipe the sidewall clean with a cloth or brush. If the code is still illegible, a tire shop can help you locate and read it, or they can tell you the age of your tires by examining them directly.
Understanding the four-digit date format
The four-digit manufacturing date uses a two-digit week number followed by a two-digit year. Weeks are numbered 01 through 53, with 01 being the first week of January and 53 being the last week of December (though not every year has a week 53). The year is shown as the final two digits only — so a 2015 tire shows "15", a 2020 tire shows "20", and a 2024 tire shows "24".
Here are some examples: a code ending in 0520 means week 05 of 2020 (early February 2020). A code ending in 5223 means week 52 of 2023 (late December 2023). A code ending in 1018 means week 10 of 2018 (early March 2018). Once you identify the last four digits, you can quickly calculate the approximate month and year the tire was manufactured.
If you need the exact date rather than just the week, you can count forward from January 1st of the year shown. Week 01 starts around January 1st, week 26 is around mid-June, and week 52 is around late December. This gives you a rough calendar month for the manufacturing date.
Why tire age matters beyond tread depth
Tire rubber is a compound that hardens and becomes brittle as it ages, even if the tire sits unused or the tread depth is still legal. This degradation happens because of exposure to heat, sunlight, and oxygen — not just from driving. A tire that looks fine on the outside may have internal cracks or weakened sidewalls that increase the risk of blowouts or sudden failure.
This is why age-based replacement is separate from tread-depth replacement. A tire with 6/32 inch of tread remaining may still be legal to drive on, but if that tire is ten years old, most manufacturers recommend replacing it anyway. Conversely, a tire with plenty of tread but manufactured eight years ago should be inspected closely and replaced soon, even if it looks new.
Tires stored in a garage or used only occasionally still age. A spare tire in your trunk or a set of winter tires in storage will degrade over time. Checking the manufacturing date on all your tires — including spares — helps you plan replacement before a tire fails unexpectedly.
What to do if your tires are older than recommended
If you discover that your tires are six years old or older, have them inspected by a tire shop or mechanic. They can look for visible cracks, bulges, or other signs of damage that indicate the tire is no longer safe. Even if the inspection shows no obvious problems, plan to replace the tires within the next year or two, depending on how much you drive.
If your tires are ten years old or older, replacement is strongly recommended regardless of tread depth or appearance. At this age, the risk of failure increases significantly. Do not wait for a problem to develop — schedule replacement at your convenience rather than dealing with a blowout on the road.
Keep in mind that the manufacturing date is different from the purchase date. A tire sold to you in 2024 may have been manufactured in 2022 if it was in inventory for two years. Always check the DOT code on new tires before installation to confirm they are recent. Most tire shops will replace tires that are more than a few years old if you ask, even if they are still in stock.
Checking the date on used or replacement tires
If you are buying used tires or having tires replaced, check the manufacturing date before you commit to the purchase or installation. A used tire that is only two years old may be a good value, but a used tire that is seven years old is approaching the end of its safe life. Ask the seller or shop for the DOT code, or inspect the tires yourself if possible.
When buying new tires, confirm that the manufacturing date is recent — ideally within the last year. Tires that have been in a warehouse for three or four years may have already begun to degrade, even though they are technically new. A reputable tire shop will stock fresh inventory, but it is worth asking or checking the sidewall yourself.
If you are replacing only one or two tires, try to match the age of the remaining tires as closely as possible. Mixing very old tires with new ones can create uneven wear and handling problems. If the other tires are more than five years old, consider replacing all four at once for safety and performance.
Frequently Asked Questions
Can I drive on a tire that is ten years old if the tread is still good?
Most manufacturers recommend against it. Even with good tread, rubber hardens and becomes more prone to failure after ten years. If your tires are this old, have them inspected by a professional and plan to replace them soon, regardless of tread depth.
Does the manufacturing date change if a tire is stored or not driven?
No. The manufacturing date is fixed when the tire leaves the factory and does not change based on how much you drive or how long the tire sits. Age is measured from the manufacturing date, not from installation or first use.
What if the DOT code is worn off or unreadable?
A tire shop can examine the tire and estimate its age based on the condition of the rubber and other markings. If the code is completely gone, the tire is likely very old and should be replaced. Do not attempt to drive on a tire if you cannot verify its age and condition.
Is there a difference between a tire made in week 01 versus week 52 of the same year?
Yes — a tire made in week 01 is about a year newer than one made in week 52 of the previous year. If you are comparing two tires and one is from week 01 of 2023 and the other is from week 52 of 2022, the first one is only about a month newer, not a full year.
Should I replace all four tires at once if they are the same age?
If all four tires are the same age and show similar wear, replacing them together is ideal for safety and handling. If only one or two are damaged or worn, you can replace just those, but try to match the age of the new tires to the remaining ones as closely as possible.