A tire can look fine — good tread, no visible damage — and still be too old to trust. Rubber ages with heat, sunlight and time, and the internal structure can weaken long before the tread wears out. Every tire sold in the United States carries a date code that tells you exactly when it was made. This calculator decodes that code, works out the tire's age today (or on any date you choose) and shows when it reaches the six- and ten-year marks that vehicle and tire makers refer to.
How to use the tire age calculator
- Find the DOT number on the tire's sidewall: the letters DOT followed by a string of letters and digits. The last four digits are the date code (sometimes only on the inner sidewall).
- Enter the four digits, for example 2319.
- Optionally pick a date to check the age on, otherwise today's date is used.
- Read the manufacture date, the age and the status, and the dates the tire reaches six and ten years.
To judge wear as well as age, see the tire tread wear calculator; for correct inflation, the tire pressure calculator.
Tire age formula
Year = 2000 + last two digits
Made ≈ 1 January of that year + (week − 1) × 7 days
Age = (today − made) ÷ 365.25 days
- Codes made before 2000 have only three digits and are far too old to use
- The week is approximate to within a few days; the age is accurate to about a week
Worked example: date code 2319
- Week: 23; year: 2000 + 19 = 2019.
- Made around: 1 January 2019 + 22 weeks = 4 June 2019.
- Age on 15 October 2026: 2,690 days ÷ 365.25 = 7.4 years (7 years, 4 months).
- Six-year mark: June 2025 — already passed; ten-year mark: June 2029.
Sample codes
These rows decode sample codes and show their age on 15 October 2026. Values were calculated with the formula above.
| Date code | Meaning | Made around | Age on 15 Oct 2026 | Status |
|---|---|---|---|---|
| 0123 | Week 1, 2023 | January 2023 | 3.8 years | Under 6 years |
| 2520 | Week 25, 2020 | June 2020 | 6.3 years | Past 6 years |
| 1018 | Week 10, 2018 | March 2018 | 8.6 years | Past 6 years |
| 4915 | Week 49, 2015 | December 2015 | 10.9 years | Past 10 years |
| 0222 | Week 2, 2022 | January 2022 | 4.8 years | Under 6 years |
How old is too old?
There is no single legal age limit for tires in the United States, and sources differ on what the safety agencies recommend. What is widely reported is manufacturer advice: many vehicle makers, including Ford, Nissan, Mazda and Mercedes-Benz, tell owners to replace tires six years after they were made regardless of tread depth, while some tire makers say a tire can serve up to ten years provided it is inspected every year after the fifth. Your owner's manual is the best authority for your car, and a tire shop can inspect older tires for cracking, bulges and sidewall damage.
Age matters because tire rubber slowly hardens and oxidizes, and heat speeds it up — tires in hot climates age faster. A tire that has been stored in the garage, or a spare that has never touched the road, ages too. Tires bought as “new” can already be a year or two old, so check the date code when you buy: a tire made in the last year or two is a better buy than an old one on discount.
Age is only one factor. Check tread depth, inflation and visible damage as well, and consider the tire's load and speed ratings with the load index and speed rating calculators. When in doubt, replace.
Sources
The four-digit WWYY date code format is part of the US Department of Transportation tire identification number (49 CFR 574). The six-year and ten-year guidance reflects advice reported from vehicle and tire manufacturers (for example Ford, Nissan, Mazda, Mercedes-Benz, Continental and Michelin); the US NHTSA has said that age recommendations are for manufacturers to set, so follow your vehicle's manual. Table values were calculated with the formula shown.
Frequently asked questions
How do I find the tire’s manufacture date?
Look on the sidewall for the letters DOT followed by a code. The last four digits are the date: the first two give the week and the last two the year. 2319 means the 23rd week of 2019.
How old is too old for a tire?
There is no single legal limit. Many vehicle manufacturers (for example Ford, Nissan, Mazda and Mercedes-Benz) advise replacing tires six years after manufacture whatever the tread, and some tire makers say tires can last up to ten years with annual inspections after the fifth. Follow your owner’s manual.
What if the code has only three digits?
Three-digit date codes were used on tires made before 2000. Such tires are far past any recommended age and should be replaced.
Does age matter if the tread is good?
Yes. Rubber hardens and develops cracks with time, heat and sunlight, even when the tire is barely used. Good tread does not show internal aging, so check the sidewall and have older tires inspected.
Do spare tires age too?
Yes. A spare that has never touched the road ages in the same way and should be checked against the same guidance.