How to find the DOT code on your tire
- Look at the sidewall for a code starting with DOT, followed by 2-3 groups of letters/numbers (plant code, size code, optional manufacturer code) and ending in the date code.
- The full code (all groups) is often molded on only ONE sidewall -- frequently the inside-facing one -- so you may need a flashlight or mirror, or to turn the wheel.
- The date code is always the LAST group: 4 digits since 2000, or 3 digits before 2000.
- Type just those last digits above (or paste the whole DOT string -- the tool finds the date code either way).
Example: 2319 decoded
Week 23 of 2019 -- approximately June 3-9, 2019. As of September 2026, that's about 7.3 years old. The tool above recalculates this using today's actual date for whatever code you enter.
Pre-2000 tires: 3-digit codes
Before 2000, the date code was only 3 digits: the first 2 are the week, but the last digit gives only the final digit of the year, so the decade is ambiguous -- 237 could be week 23 of 1987 or 1997. Many 1990s tires carry a small triangle (◻ or ▲) molded next to the code specifically to mark that decade, but not every tire has it, and there's no way to be 100% certain from the digits alone. Practically, it rarely matters which decade: a 3-digit-code tire is decades old and should not be in service.
How old is too old? What the sources say
There is no single US federal law that sets a maximum tire age. The guidance below is quoted from named sources, not stated as this site's own rule or as law:
- NHTSA (the US National Highway Traffic Safety Administration) has warned that aged tires are a safety concern, and its own guidance highlights that several vehicle manufacturers recommend replacing tires at a set age regardless of tread depth.
- Manufacturer guidance commonly recommends having tires inspected by a specialist starting around 5-6 years from the manufacture date, and replacing them by 10 years from that date even if they look fine and were rarely used (including spares).
| Source | Link |
|---|---|
| NHTSA, "Tire Service Life" | https://www.nhtsa.gov/tire-safety/tire-service-life |
| Michelin, "How Old Are My Tires?" | https://www.michelinman.com/auto/auto-tips-and-advice/tires-101/tire-age |
Always confirm against your own vehicle owner's manual and your tire's specific manufacturer guidance -- ages can vary by tire type and use case (e.g. a rarely-used spare vs. a daily-driven tire).
Related tire tools
- Tire size calculator: full dimensions of a tire size, plus equivalent sizes.
- Tire speed rating chart: what the letter after the load index means.
- Tire load index chart: how much weight your tires are rated to carry.
Frequently asked questions
How do I read a tire date code?
The date code is the LAST group of digits in the DOT number. For 4 digits (tires from 2000 onward), the first 2 are the week and the last 2 are the year -- e.g. 2319 means week 23 of 2019 (approximately June 3-9, 2019). As of September 2026, that example works out to about 7.3 years old.
Where do I find the DOT code on the tire?
It starts with "DOT" and is molded into the sidewall, usually on the INSIDE-facing sidewall (the one that faces the vehicle when mounted) -- some tires only have the full code on one side and a shorter partial code on the other. You may need to turn the wheel or use a flashlight/mirror to see it.
What do 3-digit date codes mean?
Tires made before 2000 used a 3-digit code: the first 2 digits are still the week, but the last digit is only the LAST digit of the year, so the decade is ambiguous from the digits alone (e.g. 237 could be week 23 of 1987 or 1997). Many (not all) 1990s tires carry a small triangle molded next to the code to mark that decade. Either way, a tire this old is far past any recommended service life.
How old is too old for a tire?
There's no single US federal law setting a maximum tire age, but NHTSA has warned that aged tires are a safety concern and points to vehicle manufacturers who recommend replacement well before the tread wears out -- commonly citing inspection after about 5-6 years and replacement by 10 years from the manufacture date, regardless of tread depth or apparent condition, since rubber compounds degrade with age (heat, UV and ozone exposure) even when a tire is barely used. Always check your own vehicle and tire manufacturer's specific guidance.
Does a tire's age matter if the tread still looks fine?
Yes -- tread depth and age are different risks. Rubber hardens and can develop internal cracking (dry rot) with age regardless of how many miles are on the tire, which raises the risk of a sudden failure, especially at highway speed or under heat. This is why manufacturer guidance uses the manufacture date, not just tread wear, as a replacement trigger.
Does this apply to my spare tire too?
Yes, especially to a spare. A spare often has very little tread wear but can still be well past its age limit sitting in the trunk or under the vehicle, exposed to heat cycles for years. Check its DOT code the same way -- don't assume 'low mileage' means 'safe.'
Is the date code the same as a recall or manufacturing defect code?
No. The date code only tells you WHEN a tire was made. If you want to check for an active recall, use the DOT number (or the full tire identification number) with NHTSA's tire recall lookup, separate from what this tool decodes.
Why does the tool show an approximate date range, not an exact date?
Tire manufacturers don't publish an exact day-by-day standard for which calendar dates fall in 'week 23,' so this tool approximates it using standard (ISO-style) week numbering. It's precise enough to judge age, but treat the exact start/end days as approximate.