Tire DOT Code Decoder – Tyre Age, Date & Plant Lookup

Tire DOT code decoder: how old are your tyres?

This tire DOT code decoder reads the Tire Identification Number moulded into every tyre sold in the United States — and on most tyres worldwide — and tells you the week and year it was made, how old it is today and which factory built it. Type the code after the letters DOT, or just its last four digits, and it does the rest.

A tire DOT code lookup matters because rubber ages even when the tread looks good, and a “new” tyre can sit in a warehouse for years. The decoder pairs the date with the published age guidance from tyre and vehicle makers, and checks the plant code against NHTSA’s register of over 1,200 tyre factories.

How to read a tyre DOT code

1. Find the oval or line of text beginning DOT on the tyre’s sidewall; the full code with the date is often only on one side.
2. Type everything after DOT into the box — spaces don’t matter — or just the final four digits.
3. Read the week and year of manufacture and the tyre’s age; set another date if you want the age at a past or future point.
4. Check the plant row to see the manufacturer and country, and read the age advice underneath.

Tyre DOT Code Decoder features

Tire DOT code meaning

US rule 49 CFR 574.5 sets out the Tire Identification Number. In the 13-symbol format used for new plant codes since 2025:

1. DOT — the tyre meets US Department of Transportation safety standards.
2. Plant code — three symbols (two on older tyres) assigned by NHTSA to the factory.
3. Manufacturer’s code — six symbols the maker uses for size, type or batch; older tyres have a two-symbol size code and an optional code instead.
4. Date code — four digits, week then year: 2321 is week 23 of 2021. Week 01 is the first full Sunday-to-Saturday week of the year.

When is a tyre too old?

There is no single rule, and the advice differs between companies:

• Michelin: have tyres inspected at least once a year after five years of service, and replace them ten years after the date of manufacture whatever the tread depth — spares included.
• Bridgestone/Firestone (technical bulletin on tyre service life): replace tyres made more than ten years ago, or sooner if the vehicle maker says so.
• Many vehicle makers, including Ford, Nissan and Mercedes-Benz, tell owners to replace tyres six years after production.
• The law: the US has no federal age limit; in the UK, tyres ten or more years old have been banned on the front axles of lorries, buses and coaches since February 2021.

Pre-2000 codes and other quirks

Tyres made before 2000 used a three-digit date code (week plus the last digit of the year), sometimes followed by a small triangle for the 1990s, so 298 means week 29 of 1988 or 1998. Plant codes became three symbols for new assignments from 13 April 2025; most existing two-symbol codes simply gained a leading 1. To check size and load ratings, use the tyre size calculator and the load index and speed rating chart.