Find out exactly how old your tires are. Type the 4-digit DOT date code from the sidewall and get the week and date they were made, their age today and when to replace them.
Last updated:
Example: 2321 = week 23 of 2021. You can paste the whole DOT number.
Enter your values to see the result.
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How to use the Tire Age Calculator
Find the DOT code on the tire sidewall; it starts with "DOT". The date code is the last 4 digits, often inside an oval.
Type the 4 digits (or paste the whole DOT number) into the box.
Choose a replacement guideline; 6 years is common vehicle-maker advice, 10 years the maximum.
Read the age, manufacture week and replace-by date.
Repeat for each tire, including the spare: tires on one car can have different ages.
How to decode a DOT tire code
The full DOT Tire Identification Number looks like DOT U2LL LMLR 2321: the first characters identify the plant, then size and manufacturer codes, and the last four digits are the date code.
In 2321, 23 is the ISO week and 21 the year (2021). Week 1 is the week containing January 4.
Age = check date − Monday of the manufacture week. Replace-by = manufacture date + your guideline (6 years is common; 10 years is the usual maximum).
Example date codes
Code
Week / year
Week starts
6-year replace-by
0118
Week 1, 2018
Jan 1, 2018
Jan 2024
2620
Week 26, 2020
Jun 22, 2020
Jun 2026
2321
Week 23, 2021
Jun 7, 2021
Jun 2027
4522
Week 45, 2022
Nov 7, 2022
Nov 2028
1024
Week 10, 2024
Mar 4, 2024
Mar 2030
Age guidelines are not a substitute for inspection: replace tires sooner if tread is worn to 2/32 in (1.6 mm), or if you see cracks, bulges, cuts or vibration.
Frequently asked questions
How do I read the tire date code?
Look for the letters DOT on the sidewall. The last four digits are the date code: the first two are the week and the last two are the year. For example, 2321 means the 23rd week of 2021, which started on Monday, June 7, 2021.
What if my tire only has a 3-digit date code?
Tires made before 2000 used a 3-digit code (two digits for the week, one for the year). Any tire with a 3-digit code is now more than 25 years old and should be replaced.
How old is too old for a tire?
Many vehicle makers recommend replacing tires about 6 years after manufacture, and tire makers generally say no tire should stay in service beyond 10 years, regardless of tread. After 5 years, have tires inspected at least once a year.
Why do tires age if they have plenty of tread?
Rubber compounds oxidize and lose flexibility over time from heat, sunlight and ozone. Aged tires can crack and are more prone to tread separation, even if they look fine. Heat and long storage speed this up.
Why is the date code only on one side of the tire?
U.S. rules require the full DOT number with the date code on one sidewall only, so it may be facing the inside of the car. Check the other side, or look from under the vehicle if you can't find it.
Does the spare tire need replacing too?
Yes. A spare ages even if it has never been used, so check its DOT code too. A 10-year-old spare can fail just when you need it.
How old can a new tire be when I buy it?
There is no legal limit, and tires stored properly age slowly, but check the date code before you buy so you know when your replacement window starts. If a "new" tire is several years old, ask for a fresher one.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.