TireGeoCalcHow Old Is Too Old for Tires? How to Read the DOT Date
You can find tire age by reading the four-digit date code at the end of the DOT sequence on the sidewall. According to NHTSA, some vehicle and tire manufacturers recommend replacing tires that are 6 to 10 years old, regardless of treadwear.
The date code tells you how old a tire is, whatever its tread depth looks like. Check it before you buy tires, and again when a tire has been on the vehicle for several years.
Why does tire age matter even with deep tread?
Tread depth only tells you how much rubber is left on the surface. It does not tell you how many years the tire has been in use, so the two checks are separate.
Bridgestone Americas states that, according to industry standards, tires do not remain in service beyond 10 years from the date of manufacture. The 6 to 10 year range is a manufacturer guideline, not a legal rule. For your vehicle, check the owner's manual or ask the vehicle or tire manufacturer.
Where is the DOT date code located?
The date is part of the Tire Identification Number (TIN) molded into the sidewall. Tire Rack explains that the TIN is the letters DOT followed by 8 to 13 letters and digits.
NHTSA states that the last 4 digits of the TIN show the week and year of manufacture. According to NHTSA's Tire Buyer's FAQ, the TIN can be missing from one side of the tire, so check both sidewalls.
Continental describes its own code format this way: the week is at positions 4 and 5, and the year at positions 6 and 7. Continental also notes that a manufacturing year can have up to 53 weeks.
How do you calculate tire age step by step?
- Find the DOT marking. Locate the letters DOT on the sidewall.
- Find the final digits. Look at the last four digits of the sequence.
- Read the manufacturing week. The first two digits indicate the manufacturing week.
- Read the manufacturing year. The final two digits indicate the manufacturing year.
Example: Decoding date codes 2319 and 0508
For example, date code 2319 represents week 23 of 2019. The first 2 digits (23) are the week and the last 2 digits (19) are the year.
Date code 0508 represents week 5 of 2008. The first 2 digits (05) are the week and the last 2 digits (08) are the year.
How do modern date codes compare with older formats?
The table compares the four-digit format used since 2000 with the older three-digit format, as documented by Tire Rack.
| Period | DOT code example | Week digits | Year digits | Decoded date |
|---|---|---|---|---|
| Since 2000 | 2319 | 23 (first 2 digits) | 19 (last 2 digits) | Week 23 of 2019 |
| Since 2000 | 0508 | 05 (first 2 digits) | 08 (last 2 digits) | Week 5 of 2008 |
| Before 2000 | 3-digit code | 2 digits | 1 digit | Week and a one-digit year |
Calculated dimensions
- Period
- Since 2000
- DOT code example
- 2319
- Week digits
- 23 (first 2 digits)
- Year digits
- 19 (last 2 digits)
- Decoded date
- Week 23 of 2019
- Period
- Since 2000
- DOT code example
- 0508
- Week digits
- 05 (first 2 digits)
- Year digits
- 08 (last 2 digits)
- Decoded date
- Week 5 of 2008
- Period
- Before 2000
- DOT code example
- 3-digit code
- Week digits
- 2 digits
- Year digits
- 1 digit
- Decoded date
- Week and a one-digit year
Tire Rack explains that date codes from before 2000 had 3 digits instead of 4: 2 for the week and 1 for the year.
What warranty terms and age limits do manufacturers set?
Tire Rack explains that most tire manufacturers offer a warranty of 4 years from the purchase date or 5 years from the week of manufacture, whichever is longer. Read the warranty that came with your tires for the exact terms.
When shopping for pre-owned tires, use the used tire check to inspect age and physical condition. To read other sidewall designations, visit our guide on how to read a tire sidewall. If you plan to change tire dimensions, compare sizes in our tire size calculator.
Frequently asked questions
Do tires expire even if the tread looks deep?
They can. NHTSA says some vehicle and tire manufacturers recommend replacing tires that are 6 to 10 years old, regardless of treadwear. Check your owner's manual for your vehicle maker's advice.
Why can't I find the date code on one side of the tire?
The TIN may appear on only one sidewall. Look at the other side of the tire.
How do you identify a tire made before the year 2000?
Its date code has 3 digits instead of 4, so it has no two-digit year. The table above shows the layout.