How old is your tyre?
The DOT code on the sidewall gives the week and year of manufacture. Type the last 4 digits — off the car or from an ad — and get the calendar interval, today's age, and whether that code can exist.
DOT 2424 = week 24 of 2024, that is 16–22 June 2024.
DOT calculator
Where the code sits on the sidewall
Look for a small oval with DOT, followed by letters and digits. The last group of four digits is the date; the rest identifies the plant and the batch:
If the marking is missing from the visible side, check the other sidewall. Check all four tyres plus the spare: used cars often arrive with mixed ages.
Worked codes
The most common shapes, verdict included. Your code is missing? Type it in the calculator above.
| Code | Week | Interval | Status |
|---|---|---|---|
| 2424 | Week 24 of 2024 | 16–22 June 2024 | Valid code |
| 1226 | Week 12 of 2026 | 22–28 March 2026 | Valid code |
| 5224 | Week 52 of 2024 | 29 December 2024 – 4 January 2025 | Valid code |
| 4819 | Week 48 of 2019 | 1–7 December 2019 | Valid code |
| 0121 | Week 1 of 2021 | 3–9 January 2021 | Valid code |
| 4714 | Week 47 of 2014 | 23–29 November 2014 | Valid code |
| 5323 | Week 53 of 2023 | 31 December 2023 – 6 January 2024 | Valid code |
| 5324 | — | — | Week missing in 2024 |
| 0024 | — | — | Week 00 does not exist |
| 1252 | — | — | Future code |
How a code translates
The first two digits are the week, the last two the year: 2424 is week 24 of 2024. The DOT week starts on Sunday and ends on Saturday, and 01 is the first full week of the year — the January days before the first Sunday belong to the last week of the previous year. The US regulation gives the example 0109 itself: 4–10 January 2009.
interval = the year's first Sunday + (week − 1) × 7 days … +6 days
For the same reason, only years with 53 Sundays have 53 weeks; in other years a code like 5324 does not exist. The result is a seven-day window, not the exact day of manufacture, and the age counts from both ends — hence the day interval. The 5- and 10-year marks on the axis are Michelin's recommendation: a yearly specialist check after five years of service, replacement ten years after manufacture whatever the tread.
Frequent questions
What does DOT 2424 mean?
That the tyre was made in week 24 of 2024, about 16–22 June 2024. The first two digits (24) are the week, the last two (24) the year 2024.
Where do I find the DOT code on a tyre?
On the sidewall, in a small oval: the letters DOT followed by letters and digits. The last four digits are the manufacturing date. If it is missing from the visible side, check the other sidewall.
What about week 53? Why do some 53 codes not exist?
DOT weeks start on Sunday, and 01 is the first full week of the year. Only years with 53 Sundays have a week 53: 5323 exists (31 December 2023 – 6 January 2024), 5324 does not.
My code looks like it is from the future. How?
Usually a misread digit or a typo in the ad: a week that has not arrived yet gives a future code. Check the digits on the sidewall itself.
How many years does a tyre last?
Michelin recommends a yearly check by a specialist after five years of service and replacement ten years after manufacture, whatever tread is left. The calculator marks both points on the age axis.
I found only three digits instead of four. What does that mean?
A tyre made before 2000, so over 25 years old. Type the three digits in the calculator for the verdict; such a tyre gets replaced.
Sources and method
- The week + year rule, the Sunday–Saturday week, and the 0109 = 4–10 January 2009 example come from 49 CFR § 574.5, the US tyre identification requirements. The same rule appears in the European Commission's questions on the manufacturing date.
- The 5- and 10-year marks are Michelin's recommendation: a yearly specialist inspection after five years of service, replacement ten years after manufacture.
- Every interval on the page — the example, the table, and the answers — follows the same rule and is checked automatically with each change.