Every tire built since 2000 wears its birthday on the sidewall. The last four digits of the DOT code are week + year of manufacture: 2419 means week 24 of 2019, a tire built in mid-June 2019 — about 7 years 2 months old as of late August 2026. That number matters more than most drivers expect, because manufacturers including Michelin and Continental put a 10-year age limit on their tires regardless of tread, and many retailers draw the line at 6 years. Here's how to find the code, read it in seconds, and know when a "fine-looking" tire is actually due for the bin.
Find the raised letters DOT on the sidewall and read the character string that follows — 11 or 12 characters in a full code, encoding the plant, tire size, and manufacturer. The final four are the date. The catch: the complete DOT number is stamped on only one sidewall, and carmakers mount that side inward about half the time. If the outer sidewall shows a stubby partial code, the full string is on the tire's inner face — photograph it from beside the fender with a phone flash, or crawl partway under with the parking brake set.
One more wrinkle from the used-car lot: sellers sometimes mount tires so the date faces in, deliberately. If you can't find a date code on any visible sidewall, treat that as information.
Four digits, first two = week, last two = year since 2000. The exact day isn't stamped, so a code maps to the start of a build week:
| DOT code | Means | Built (approx.) |
|---|---|---|
| 0525 | Week 5, 2025 | Jan 29, 2025 |
| 1921 | Week 19, 2021 | May 7, 2021 |
| 2419 | Week 24, 2019 | Jun 11, 2019 |
| 3615 | Week 36, 2015 | Sep 3, 2015 |
| 3206 | Week 32, 2006 | Aug 6, 2006 |
Three digits instead of four? The tire predates 2000: two week digits plus one year digit for the 1990s, marked with a small triangle stamp. A 161 with the triangle is week 16 of 1991. There is no scenario where a 3-digit tire belongs on the road in 2026.
Type the last 4 digits of your DOT code and get the build date, exact age, 6-year and 10-year thresholds, and a verdict — spare tire included.
Open the Tire DOT Age Decoder →Not on any federal calendar — NHTSA sets no expiration date, and tires aren't stamped with one. But the industry's own guidance functions like one:
Why the limits when the tread looks deep? Aging is an inside job. Ozone, UV, and repeated heat cycles dry out the rubber and degrade the steel and nylon belts sandwiched inside the casing until the structure lets go — a failure mode tread depth can't see. Heat is the accelerant, which is why Phoenix ages out tires years before Minneapolis does and why the spare, cooked under a trunk lid for a decade, is so often the worst tire on the car.
Both clocks run and whichever expires first decides. A typical all-season tire lasts roughly 45,000-60,000 miles, which for an average 12,000-mile-a-year driver is 4-5 years — comfortably inside the age limits. The year-clock cases are the opposite: the garage-queen convertible with 4,000 miles on 2016 tires, the trailer that sits loaded all summer, the daily driver that only does 6,000 miles a year. Deep tread on a 9-year-old casing is a coin you shouldn't flip; budget the replacement and sleep better.
Buying new tires? Fresh rubber is part of the deal: insist on a code within the last year or two. A "new" tire sitting in a warehouse since 2022 has already spent 20% of its safe life in the dark. When you're pricing the set, the new tires cost calculator prices installed sets by size and type, and if you're changing dimensions the tire size calculator shows the speedometer effect before you buy.
The used-tire market runs on tread depth, and that's exactly backwards — price the age, then the tread. A half-tread 3-year-old tire at $40 can be fair value; a 7/32-inch 7-year-old at the same price is paying new-tire money for the risk. Walk away from anything inside 18 months of the 10-year limit, any tire with a 3-digit code, and any seller who can't produce the DOT side of the sidewall. Match codes across a pair too: a 2019 and a 2023 on the same axle will age out two years apart, which is fine, but a 2008 and a 2023 pair is someone else's problem becoming yours.
Look for the letters DOT stamped on the sidewall, then read to the end of the character string that follows. The last four digits are the date code. The full DOT number is stamped on only one sidewall — if the side you can see shows just a few characters, the complete code is on the tire's inner side, so kneel by the fender or photograph it from under the car.
2419 means week 24 of 2019 — the tire was built in mid-June 2019, making it about 7 years 2 months old as of late August 2026. First two digits are always the week, last two are the year since 2000.
In miles, a typical all-season tire lasts 3-5 years of average driving (roughly 45,000-60,000 miles). In calendar age, tire manufacturers including Michelin and Continental set 10 years from date of manufacture as the hard limit, with annual professional inspections after year 5 — and many retailers recommend replacing at 6 years, especially in hot climates. Whichever limit the tire hits first wins.
Tread measures the outside; aging happens inside. Ozone, UV, and heat cycles dry out the rubber compounds and degrade the steel and nylon belts layered inside the tire until the structure can't hold together — which is why an old low-mileage tire can fail with deep tread. Heat accelerates everything, so desert-climate tires age on a faster clock.