How to Read a Tire Size (225/65R17 Explained)
Every tire has a code on its sidewall, like 225/65R17 102H. It looks cryptic, but each part tells you something specific. Here is how to read it.
Width: 225
The first number is the tire's width in millimeters, measured sidewall to sidewall. A 225 is 225 mm wide, about 8.9 inches.
Aspect ratio: 65
The second number is the sidewall height as a percentage of the width. Here the sidewall is 65% of 225 mm, about 146 mm. Lower numbers mean a shorter, sportier sidewall; higher numbers mean more cushion.
Construction and wheel diameter: R17
R means radial construction, which nearly every modern passenger tire uses. 17 is the wheel diameter in inches the tire fits.
Load index and speed rating: 102H
The load index (102) is how much weight each tire can carry; 102 equals 1,874 lb. The letter is the maximum speed rating; H is up to 130 mph. Always replace with a load index and speed rating at or above what your vehicle calls for.
Where to find your size
- On the sidewall of your current tires.
- On the sticker inside the driver's door jamb.
- In your owner's manual.
Not sure? Call or text us at (571) 402-8698, or use the finder on tread4life.com to search by vehicle.