How do I read a tire date code?

Four digits, since 2000: the first two are the week of the year (01 to 53) and the last two are the year. 2519 is the 25th week of 2019. 0824 is the 8th week of 2024.

What does a three digit date code mean?

Three digits, before 2000: the first two are the week and the LAST DIGIT ALONE is the year, which does not say which decade. 228 could be the 22nd week of 1998, 1988 or 1978. A three digit date code means the tire predates 2000 whatever else it says, which on any road tire is reason enough to replace it.

What do the characters before the date code mean?

The first two or three identify the plant that built the tire. The next two are the manufacturer's own code for the size, and the ones after that are an optional code for the tire line. Only the plant code and the date code are standardised; the size and type codes are assigned by each manufacturer and mean different things at different brands.

DOT tire date code

The only marking on a tire that says how old it is. Type yours in and it will be read back, including the case where the code cannot tell you which decade it means.

Date code (the last three or four digits of the DOT code)

Four digits for a tire built in 2000 or later, three for anything older.

The two formats

Four digits, since 2000: Four digits, since 2000: the first two are the week of the year (01 to 53) and the last two are the year. 2519 is the 25th week of 2019. 0824 is the 8th week of 2024.
Three digits, before 2000: Three digits, before 2000: the first two are the week and the LAST DIGIT ALONE is the year, which does not say which decade. 228 could be the 22nd week of 1998, 1988 or 1978. A three digit date code means the tire predates 2000 whatever else it says, which on any road tire is reason enough to replace it.

Check the other side before you conclude anything

The date code is only required on one sidewall. Find DOT on one side with no date after it and you are looking at the wrong side of the tire - check the other one before concluding the tire is unmarked.

The whole code, character by character

Segments of a DOT tire identification number
Segment	Length	What it says
DOT	3 letters	The tire is certified to United States federal motor vehicle safety standards. Without it the tire is not legal for road use in the US.
Plant code	2 or 3 characters	The factory that built the tire. Two characters historically; a third was permitted from April 2015, so both lengths are in circulation.
Size code	2 characters	The manufacturer's own code for the size. It is not standardised - each manufacturer assigns these itself, so the same two characters mean different sizes at different brands.
Type code	up to 4 characters, optional	Optional manufacturer code for the tire line, used for internal tracking. Carries no consumer meaning and is absent on some tires.
Date code	4 digits (3 before 2000)	Week and year of manufacture. This is the part that tells you the tire's age, and the only part of the code most people ever need.

The letters G, I, O, Q, S and Z are not used in DOT codes, because they read too easily as 6, 1, 0, 0, 5 and 2. A character you read as one of those is a digit.

Letters never used: G, I, O, Q, S, Z.

What the date does not tell you

A date code is a manufacturing date, not an expiry date. How long a tire remains serviceable depends on storage, load, inflation, heat, ultraviolet exposure and damage, and the vehicle and tire manufacturers publish their own replacement guidance. This page reads the code; it does not decide when a tire is finished.

Common questions

How do I read a tire date code?: Four digits, since 2000: the first two are the week of the year (01 to 53) and the last two are the year. 2519 is the 25th week of 2019. 0824 is the 8th week of 2024.
What does a three digit date code mean?: Three digits, before 2000: the first two are the week and the LAST DIGIT ALONE is the year, which does not say which decade. 228 could be the 22nd week of 1998, 1988 or 1978. A three digit date code means the tire predates 2000 whatever else it says, which on any road tire is reason enough to replace it.
Why can I not find the date code on my tire?: The date code is only required on one sidewall. Find DOT on one side with no date after it and you are looking at the wrong side of the tire - check the other one before concluding the tire is unmarked.
What do the characters before the date code mean?: The first two or three identify the plant that built the tire. The next two are the manufacturer's own code for the size, and the ones after that are an optional code for the tire line. Only the plant code and the date code are standardised; the size and type codes are assigned by each manufacturer and mean different things at different brands.
Is there a letter O or I in a DOT code?: The letters G, I, O, Q, S and Z are not used in DOT codes, because they read too easily as 6, 1, 0, 0, 5 and 2. A character you read as one of those is a digit.

Where these figures come from

Published values here were read from 2 independent sources:

Understanding DOT Codes: Guide to Tire Identification - Wheel-Size.com, undated reference article (read 2026-08-27)
DOT code structure, plant code width, omitted letters, date code format and which sidewall carries it
5 Tips to Read the DOT Date Code - Tires Easy, undated reference article (read 2026-08-27)
DOT date code format before and after 2000, worked examples

These are independent publishers, not independent measurements. Each one reproduces a table originally set by a standards body, so agreement between them shows a value was transcribed correctly, not that the underlying table is right. Where a figure is safety relevant, check it against the tire manufacturer's own data before relying on it.

Left out on purpose

DOT plant code lookup. Plant codes are assigned and revised by the federal regulator and the published lists in circulation are incomplete and out of date; a partial list here would be worse than none.
The DOT size code and type code are manufacturer-assigned and not standardised, so they cannot be decoded from a table at all.