Four digits in an oval on the sidewall. The first two are the week of manufacture, the last two the year — so 2523 is the twenty-fifth week of 2023. It tells you how old the tyre is, and age is a separate measurement from how worn it is.
Where to look
On the sidewall, inside a small oval, at the end of a longer code. It is on one side of the tyre only, so if you cannot find it, look at the other side. It is stamped, not printed, and on a dirty tyre it is easier to feel than to see.
Why age and wear are different questions
Tread depth measures how much rubber is left. The date measures how long the compound has been ageing since it was made. A tyre can have almost full tread and be old, which happens to machines ridden a few hundred kilometres a year, and it can be nearly new and nearly worn out, which happens to machines ridden a great deal.
What the number is useful for
Two things. Knowing what you are buying: a tyre that has sat in a warehouse for years is still sold as new, and the code is the only way to know. And knowing what is on your machine now, particularly on a bike bought second-hand, where the tyres may be much older than the mileage suggests.
What a date code cannot tell you
At what age a tyre should be replaced. Tyre and machine manufacturers publish guidance on that and it varies; storage conditions change it; and it is not a figure a comparison page should invent. Read what the tyre maker and your machine’s manual say.
The other sidewall markings worth knowing
The size, the load index and the speed index are stamped alongside, and the machine’s manual states which the machine takes. Those are matching figures rather than preferences, and the manual is where they live.
Where this page and the manufacturer’s own paperwork say different things, the paperwork wins. Every weight, shell size, armour level, approval version, viscosity grade, chain pitch, pad reference and torque figure on this page comes from the maker’s own published figures, with the unit as printed and the source named. None of it is measured here, and no figure is converted into another convention, because a converted number is a different number. And the limit this page does not cross: nothing here replaces the maker’s bedding-in, torque and pressure figures. New pads do not work at full effect until the procedure their maker publishes has been followed, a fastener has a torque its maker specifies, and a tyre has a cold pressure the machine’s manufacturer sets. This page points at those documents rather than rewording them.
Questions riders send in about this
Is an old tyre with full tread safe to use?
That is a judgement this site does not make. What can be said is that the two measurements are independent, and that tyre makers publish their own guidance on age.
Do both tyres have the same date?
Rarely. They are fitted at different times and made in different batches, so each carries its own code and each is read separately.
Last reviewed 18 September 2026