How to Read a Tire Date Code [DOT Week and Year]
The tire date code is the last four digits of the DOT number on the sidewall: the first two are the week and the last two are the year, so 2319 means the 23rd week of 2019. Tires made before 2000 use three digits. The full code is often printed on one side only, so check the inner sidewall if you cannot find it, and use a flashlight at a low angle to read worn or dirty lettering.
How to read the date code
Find the letters DOT on the sidewall near the rim. A string of letters and numbers follows, and the date is the last group, often in its own oval box.
| Code | Week | Year | Made around |
|---|---|---|---|
| 0124 | 01 | 2024 | Early January 2024 |
| 2319 | 23 | 2019 | Early June 2019 |
| 4022 | 40 | 2022 | Early October 2022 |
| 5221 | 52 | 2021 | Late December 2021 |
To turn a week into a month, divide the week number by 4.3. Week 23 divided by 4.3 is about 5.3, so a little into the sixth month, June.
Three-digit date codes
Tires made before 2000 used three digits: two for the week and one for the year of the decade. A code ending 329 means week 32 of a year ending in 9, usually 1999. Tires from the 1990s often have a small triangle after the code to mark the decade. Any tire with a three-digit code is now well over 20 years old and should not be on a road vehicle.
What the rest of the DOT code means
The full code is the Tire Identification Number. In order, it contains:
- DOT: the tire meets US Department of Transportation standards.
- Plant code: two or three characters identifying the factory. Newer plants have three-character codes.
- Size code and manufacturer’s code: used for tracking and recalls.
- Date code: the last four digits.
If you register your tires or check a recall, you need the whole code, so a clear photo of it is worth taking.
Can’t find the date code?
- Check the other side. The full code with the date only has to be on one sidewall, and it is often the side facing under the car.
- Turn the wheel. For the front tires, turn the steering wheel fully to one side to bring the inner sidewall into view.
- Roll the car. The code may be at the bottom where the tire meets the ground. Move the car half a wheel turn.
- Do not forget the spare. Spare tires are often the oldest tire on the car.
How to read a worn or dirty code
- Wipe it clean with a damp cloth. Brake dust fills the lettering.
- Light it from a low angle. The characters are molded into the rubber, black on black. A flashlight held almost flat against the sidewall makes each one cast a shadow. Light from straight on makes them disappear.
- Use your phone instead of your knees. Hold the phone at the inner sidewall, zoom in, and read the code on the screen. Take a photo so you can check it again later.
- Watch for 0 and O, 1 and I, 8 and B. The date is always four digits, but the rest of the code mixes letters and numbers.
LoupeLens is handy for this: the flashlight stays on while you zoom, you can dim it to cut the shine on rubber, and the photo goes into its own album in Photos.
How old is too old?
There is no single federal expiry date for tires in the US. Rubber ages even when a tire is barely used, so many tire and vehicle makers recommend a professional inspection from about five years old and replacement 6 to 10 years after the date of manufacture, whatever the tread depth. Your owner’s manual gives the figure for your car. Look for cracks in the sidewall and between tread blocks, bulges, and hardened rubber. When buying new tires, check the date code on the tire before it is fitted.
Other numbers on the sidewall
A size like 225/60R17 99H reads as: 225 mm wide, sidewall height 60% of the width, R for radial construction, fits a 17 inch wheel, load index 99, speed rating H. For more codes on your car, including VINs and fuse box labels, see reading hidden codes on your car.
Frequently asked questions
How do I read a tire date code?
Find DOT on the sidewall and read the last four digits. The first two are the week and the last two are the year, so 1023 means the tenth week of 2023.
Where is the date code on a tire?
At the end of the DOT number, near the rim. It is often only on one side, so check the inner sidewall if the outer one shows a shorter code.
What does a three-digit tire date code mean?
The tire was made before 2000. The first two digits are the week and the last is the year of the decade. Such a tire is too old to use.
How old can tires be?
Many tire and vehicle makers recommend replacing tires 6 to 10 years after the date of manufacture, whatever the tread. Check your owner’s manual and have older tires inspected.
Can new tires be old?
Yes. A tire can sit in storage before it is sold. Check the date code before the tires are fitted and ask for recent stock if it is more than a year or two old.