How to Read Your Tire Size and Find the Age of Your Tires

Mark
May 18
2 min read

Tires might look like simple rubber circles, but they carry a lot of important information—right on their sidewalls. Whether you're shopping for new tires or just curious about the ones already on your vehicle, understanding your tire size and how to find the tire's age can help you make safer, smarter decisions.

🧠 What Does Tire Size Mean?

Take a look at your tire’s sidewall. You’ll see something like this:

P215/65R15 95H

Let’s break it down:

P – This stands for Passenger vehicle tire. (You might also see "LT" for Light Truck.)
215 – This is the tire width in millimeters, from sidewall to sidewall.
65 – This is the aspect ratio, or the height of the sidewall as a percentage of the width. In this case, it’s 65% of 215mm.
R – This indicates Radial construction, which is standard in modern tires.
15 – This is the wheel diameter in inches. So, this tire fits a 15-inch wheel.
95H – This represents the load index (how much weight the tire can handle) and the speed rating (how fast it can safely go).

If you're unsure which tire size your vehicle needs, your owner's manual will list it—or you can find it on a sticker inside your driver's side door jamb.

🔎 How to Check the Age of Your Tire

Tires don’t last forever. Even if they have good tread, old tires can become dry, cracked, and unsafe. Thankfully, every tire includes a manufacturing date right on the sidewall.

Look for the DOT code—a string of letters and numbers that starts with “DOT.” At the end of that code, you’ll find a four-digit number that tells you the week and year the tire was made.

Example: DOT U2LL LMLR 3219

32 – The tire was made in the 32nd week
19 – Of the year 2019

So, this tire was manufactured in August 2019.

🛑 When Are Tires Too Old?

Even if your tires have tread, most manufacturers recommend replacing them at 6 to 10 years old depending on storage conditions, use, and climate. Tires dry out over time and can become brittle, which increases the risk of a blowout or loss of traction.

Pro Tip: Check all your tires—even the spare! Many spares go untouched for years and may be unsafe even if unused.