What it does
Every tyre has a small oval stamp on one sidewall that starts with the letters DOT. The last four digits say when the tyre was made: the first two are the week, the last two are the year. So 2423 means week 24 of 2023. Rubber ages even when a tyre is never used, so the date matters as much as the tread.
Type the digits and the tool shows the week and year, the dates that week covers, the age in years and months, and plain advice for that age. Pair it with tread depth for the other half of a tyre check, keep the air right with tyre pressure, and see the road side in stopping distance.
How to use it
- Look at the sidewall for the letters DOT. The date is the last four digits, often inside a small oval. If you cannot see it, check the other sidewall: it is only moulded on one side.
- Type the four digits into the box.
- Read the age and the advice. If you are buying new tyres, ask for ones made in the last year or so.
What each part means
- Week: 01 to 53. Week 1 is the first week of January.
- Year: two digits, counted from 2000. Three digits instead of four means the tyre was made in the 1990s and is far too old to use.
- Age advice: under 5 years, normal checks. From 5 years, have it checked every year. At 10 years, replace it whatever it looks like. Some car makers say 6 years, so follow your manual if it is stricter.
Worked example
You type 2423. That is week 24 of 2023, about 11 to 17 June 2023. On 12 November 2026 the tyre is 3 years 5 months old, so it needs only normal checks. In 2028 it would reach 5 years and should be checked yearly.
FAQs
Does the spare tyre count? Yes. A spare ages in the boot even if it never touches the road. Check its date and pressure too.
Does hot weather matter? Heat and strong sun age rubber faster. In hot places such as the Gulf, treat the age limits as an upper limit and check tyres more often.
Why can I not find the date? The full DOT stamp is on one sidewall only, sometimes on the inside. Look at the other side, or ask a tyre shop to read it.
Is it legal to drive on an old tyre? Rules differ and most places have no age limit for cars. Safety advice is stronger than the law here: check the official source for your area.
Not safety advice. When in doubt, ask a tyre shop.
Where the numbers come from
- The date code is the last four digits of the DOT number on the sidewall: two digits for the week (01 to 53) and two for the year. Tyres made before 2000 have three digits (week, then one digit for the year in the 1990s). The week is counted from 1 January in blocks of seven days, so the dates shown are about right, to within a few days. Age advice follows commonly published maker and tyre-safety guidance as checked November 2026: check yearly from 5 years, replace at 10 years (some car makers say 6 years); check your vehicle maker and the official source. Drawings are fibub's own.
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Last updated 2026-11-12.