How To Date Tires | Read The DOT Code Right

A tire’s age comes from the last four digits of its DOT code: the first two show the week, and the last two show the year.

Tire dating sounds odd until you’re standing in a shop, looking at a stack of “new” tires, and wondering how long they’ve been sitting there. That’s when the sidewall starts to matter. The date is not hidden in a warehouse file or dealer system. It’s molded right into the tire.

If you want the plain answer, you date a tire by finding its DOT code, then reading the last four digits. A code ending in 3424 means the tire was made in the 34th week of 2024. That’s the whole trick. The rest is knowing where to look, what not to mix up, and how to use that date with tread depth, cracking, and wear.

How To Date Tires On Any Passenger Vehicle

You can date a tire in less than a minute once you know the pattern. Start at the sidewall and scan for the letters “DOT.” That marks the Tire Identification Number. The full code may appear on only one sidewall, so you may need to check the inward side of the tire if the outer side shows only a partial string.

Start With The DOT String

The DOT code is usually grouped with other molded markings. Some of those numbers describe size, load, or factory details. The date is not at the front. It sits at the end. That’s where many people get tripped up. They spot a long line of letters and numbers, grab the first set they see, and call it the age. That’s not it.

1. Find the letters DOT on the sidewall.
2. Read the full code that follows it.
3. Ignore the earlier plant and size characters.
4. Use the final four digits as the production date.

Read The Last Four Digits

The last four digits follow a fixed pattern. The first two digits are the production week. The last two digits are the year. So 0825 means week 8 of 2025. A code ending in 4719 means week 47 of 2019. Once you know that pattern, the tire’s birth date stops being a mystery.

Check Both Sidewalls Before You Give Up

This part catches people all the time. The full date code may be molded on only one side of the tire. If the visible side shows DOT plus a shorter string, roll the car a little, turn the steering, or use a flashlight to inspect the inner sidewall. On loose tires at a shop, ask to see the full TIN before you buy.

Dating A Tire By Its DOT Code Without Guesswork

The DOT date is one part of a longer identification string. That longer string tells you more than age, yet the last four digits are the piece most drivers care about. If you know what each section does, you’re less likely to read the wrong number or miss the date altogether.

What Each Part Of The Marking Means

Federal tire labeling rules use a Tire Identification Number, often shortened to TIN. The early characters identify the plant and other production details. The ending gives the week and year. That means a tire can have many letters and numbers before the date, and none of them change the week-year format at the end.

Marking Part	What It Means	Why It Matters
DOT	Shows the tire follows U.S. Department of Transportation labeling rules.	Tells you you’re reading the right string.
Plant Code	Identifies the factory where the tire was made.	Useful in recalls and production tracing.
Size Code	Links to the tire’s size grouping within the TIN.	Not the same thing as the date.
Maker Code	Extra factory or product information from the maker.	Can make the code look longer than expected.
Last Four Digits	The production date.	This is the part you use to date the tire.
First Two Of The Last Four	Week of manufacture.	Shows where in the year the tire was produced.
Last Two Of The Last Four	Year of manufacture.	Shows the tire’s age at a glance.
Partial DOT On One Side	A shortened version without the full ending.	Means you may need the other sidewall for the date.

NHTSA’s tire buyer note says the last four digits of the TIN show the week and year the tire was made, and it also points out that the full TIN may not appear on both sides. Michelin’s tire markings page breaks the same code into a plain week-year format and gives a clean sidewall reading pattern.

What The Date Tells You And What It Doesn’t

The date tells you when the tire left the mold. It does not tell you whether the tire is still fit for the road by itself. A tire with a recent date can still be wrong for your car, worn badly, patched poorly, or stored in rough conditions. An older tire with deep tread still needs a close visual check for cracking, bulges, odd wear, and hardening.

That’s why the date works best as one piece of a larger check. Use it with the vehicle placard, the owner’s manual, tread depth, sidewall condition, and the tire’s load and speed ratings. If one part is off, the date alone won’t save the deal.

Common Mistakes That Lead To The Wrong Age

Most date-reading errors come from rushing. The sidewall is busy. It has size numbers, pressure markings, service descriptions, brand names, and sometimes extra symbols packed into a tight space. If you grab a random four-digit block, there’s a fair shot you’ll date the tire wrong.

Reading Tire Size As The Date

A size such as 225/45R17 is not a date. Neither is a load index and speed rating such as 94W. Those markings tell you fitment and service limits. The date is tied to the DOT/TIN string only.

The Four-Digit Ending Is The One That Counts

When people say “read the tire date code,” they mean the final four digits at the end of the DOT sequence. If the tire does not show that ending on the side you can see, stop there and check the other sidewall. Don’t guess from the rest of the markings.

Judging By Tread Alone

Deep tread can make an old tire look young. That happens a lot with spares, trailers, low-mileage cars, and seasonal setups. A tire can age out in plain sight because it spends years sitting, heating up, cooling down, and drying out. Date, wear, and condition need to agree with each other.

Situation	What The Date Tells You	What To Do Next
Buying one new tire	Shows how fresh that single tire is compared with the others.	Match size, load rating, speed rating, and age as closely as you can.
Used car purchase	Shows whether “good tread” hides older rubber.	Read all four tires, not just one.
Trailer tires	Shows age on tires that may look barely used.	Check sidewalls for cracks and dry feel.
Spare tire	Shows how long it has sat untouched.	Inspect it before you need it on the roadside.
Seasonal tire swap	Shows the age of stored winter or summer sets.	Read the date during each swap, not after a problem starts.
Uneven wear issue	Shows age, though age may not be the root cause.	Also check alignment, inflation, and suspension.

When The Date Matters Most

The date matters most when the tire’s history is fuzzy. That includes online listings, used vehicles, closeout sales, garage finds, and spare tires that have not touched pavement in years. In those moments, the date gives you something solid. You’re no longer taking someone’s word for “pretty new.” You have the production week and year in front of you.

Buying A Single Replacement Tire

If you’re replacing one tire after a puncture or road hit, the date helps you compare the new tire with the three still on the car. You still need the same size and a matching service description, yet the week-year stamp can also tell you whether you’re buying a tire that has been sitting around longer than you expected.

Used Cars, Trailers, And Spares

These are the places where tire age gets missed. A used car can wear clean-looking tires that are older than they appear. Trailer tires can keep lots of tread because they cover fewer miles. A spare can sit untouched for years and then be asked to carry the car on the worst day of the month. Reading the date on every tire gives you a truer picture of what you’re dealing with.

A Simple Tire-Date Routine Before You Buy

You do not need a shop lift or a mechanic’s scanner for this. A slow walk, a flashlight, and thirty extra seconds will do the job.

• Read the DOT code on every tire, not just the one easiest to reach.
• Write down the last four digits from each tire.
• Compare those dates across the full set.
• Check tread depth and wear pattern right after that.
• Scan the sidewalls for cracks, bulges, or cuts.
• Match the tire size and service description to the placard and manual.

Once you know how to date a tire, you stop shopping blind. The sidewall gives you the production week and year in a form you can read on the spot. That makes it easier to judge a “new” tire on the rack, a used car in a driveway, or a spare buried under the cargo floor. One small code gives you a cleaner read on the tire in front of you, and that’s often the difference between guessing and knowing.