DOT Code on Tires Explained: How to Read It and What It Means

Every tire sold in the United States has a DOT code stamped on the sidewall. It's a short string of letters and numbers that most drivers walk past every day without a second glance — but it contains critical information about where your tire was made, when it was made, and whether it's still safe to use.

Here's how to find it, read it, and use it.

TL;DR — The Quick Answer

• The DOT code is a series of characters stamped on your tire sidewall, required by the Department of Transportation.
• The last four digits are the date code: first two = week, last two = year (e.g., 2523 = week 25 of 2023 = June 2023).
• The other segments identify the manufacturer, plant, tire size, and model.
• Decode your DOT code instantly with the free TireSpy checker — just enter the last 4 digits.
• Tires older than 6 years should be inspected; older than 10 years should be replaced.

What Does "DOT" Stand For?

DOT stands for Department of Transportation. The DOT code is mandated by the US Department of Transportation as part of federal tire safety standards. Every tire manufactured for sale in the US must carry this code, and it serves as a unique identifier that traces the tire back to its manufacturer, production facility, and exact production date.

The requirement was introduced under the National Traffic and Motor Vehicle Safety Act, and the current format — including the four-digit date code — has been in use since the year 2000.

Where to Find the DOT Code

The DOT code is molded into the sidewall of the tire — the flat rubber face between the tread and the wheel rim. Look for the letters "DOT" followed by a series of characters.

Important: The full DOT code, including the date digits, is sometimes only printed on the inboard side of the tire — the side facing the vehicle. If you see "DOT" followed by some characters but the string seems to end abruptly (fewer than 10–12 characters), walk to the other side of the tire to find the complete code.

This is a common frustration for drivers checking their tires in a parking lot. Tire manufacturers are only required to print the full code on one side, and they often choose the inner sidewall. You may need to turn your steering wheel to full lock or get down on the ground to see the inner face of the tire.

Breaking Down the DOT Code

A typical DOT code looks something like this:

DOT U2LL LMLR 2523

Each segment means something specific. Let's break it down:

Segment 1: Plant Code (2 characters)

The first two characters after "DOT" identify the manufacturing plant. This is a code assigned by the DOT to every tire factory worldwide. For example, "U2" might indicate a specific Michelin plant in South Carolina.

These codes are maintained in a public database, though most consumers will never need to look one up. The plant code becomes relevant in recall situations — if a defect is traced to a specific factory, the plant code helps identify affected tires.

Segment 2: Tire Size Code (2 characters)

The next two characters represent the tire size. This is an internal manufacturer code, not the standard tire size format (like 225/65R17) that you see elsewhere on the sidewall. It maps to the tire's dimensions within the manufacturer's system.

Segment 3: Brand and Model Code (up to 4 characters)

The next group of characters is an optional brand and model identifier assigned by the manufacturer. This code helps the manufacturer trace the tire to a specific product line during quality control or recalls.

Segment 4: Date Code (4 digits) — The Most Important Part

The last four digits of the DOT code are the date of manufacture, and this is the segment that matters most for your safety.

• First two digits = the week of manufacture (01 through 52)
• Last two digits = the year of manufacture

Examples

DOT Date Code	Week	Year	Approximate Date
0519	05	2019	Early February 2019
2723	27	2023	Early July 2023
5221	52	2021	Late December 2021
1416	14	2016	Early April 2016

A tire with the date code 1416 was made in April 2016. If you're reading this in 2026, that tire is 10 years old — past every manufacturer's recommended maximum lifespan.

Pre-2000 Tires: The 3-Digit Date Code

Before the year 2000, the DOT date code was only three digits — two digits for the week and one digit for the year. A code ending in 258 could mean week 25 of 1988 or week 25 of 1998 — there was no way to distinguish between decades.

The system was updated to four digits in 2000 to eliminate this ambiguity. If you encounter a tire with a three-digit date code, the tire is at least 26 years old and should be replaced immediately regardless of condition.

How to Decode Your DOT Code in 30 Seconds

You don't need to memorize any of this. Here's the fastest method:

1. Find the DOT code on your tire sidewall (check both sides if needed)
2. Look at the last four digits
3. Enter them into the TireSpy DOT checker

You'll get an instant result showing your tire's exact age, a safety rating (green, amber, or red) based on NHTSA guidelines and your tire type, and clear guidance on what to do next. The whole process takes about 30 seconds per tire.

Why the Date Code Matters

Rubber degrades over time through oxidation — a chemical process that hardens the compound and weakens the internal structure. This happens whether the tire is driven on daily or sitting in a warehouse. Heat, UV exposure, and ozone accelerate the process, but even a tire stored in perfect conditions will eventually become unsafe.

The NHTSA recommends replacing tires after 6 years of service. Every major manufacturer (Michelin, Bridgestone, Goodyear, Continental, Pirelli) sets a hard limit of 10 years from the date of manufacture — no exceptions, regardless of tread depth or appearance.

The DOT date code is the only reliable way to know how old your tire is. You can't judge age by looking at the tread. A tire can have 8/32" of tread depth and still be dangerously old.

Common Questions About DOT Codes

Is the DOT code the same as the tire size?

No. The tire size (e.g., P225/65R17) is printed separately on the sidewall. The DOT code is a different marking that includes the date of manufacture and manufacturing information.

What if the DOT code is worn off or unreadable?

If you can't read the DOT code, you can't verify the tire's age — and you should treat the tire as potentially unsafe. This sometimes happens on very old tires where the sidewall markings have degraded, which is itself a sign that the tire is past its useful life.

Do all tires worldwide have DOT codes?

DOT codes are required for all tires sold in the United States. Tires manufactured for other markets may carry a different identification system or may include the DOT code voluntarily. If you buy tires internationally or find tires without a DOT code, exercise extra caution.

Can a dealer sell me a tire that's already several years old?

Yes. There is no federal law restricting the sale of tires based on age. A tire manufactured 3 or 4 years ago that has been sitting in a warehouse is legal to sell as new. This is another reason to check the DOT date code on any tire you purchase — even brand-new ones from a retailer.

Check Your Tires Now

Knowing your tire's age is the first step toward knowing whether it's safe. Use the TireSpy DOT checker to decode the date in seconds — no guesswork, no math, just a clear answer.

If your tires are approaching the end of their safe lifespan, browse replacement options from trusted retailers. Most offer free shipping and can route your tires to a local installer for professional fitting.

The Bottom Line

The DOT code is stamped on every tire for a reason. The last four digits tell you exactly when your tire was born — and from that single data point, you can determine whether it's safe, aging, or overdue for replacement. Find the code, read the date, and if it's been more than 6 years, take action. It's the simplest safety check you'll ever do.