How to read your tire size

A clear tire-size photo can turn a vague inquiry into a useful quote. Look for the larger letter-and-number sequence molded into the sidewall.

Start with the size

In a size such as 225/65R17, 225 identifies the section width in millimeters, 65 is the aspect ratio, R means radial construction, and 17 is the wheel diameter in inches. Keep any prefix, such as P, LT, or ST, when you send it to us. Those markings are not interchangeable.

Keep the numbers after it, too

A service description such as 102H identifies load index and speed rating. Heavy-duty and commercial tires may also show a load range and different single/dual load ratings. Include all of that information rather than just saying “17-inch tire.”

Check the vehicle, not just one sidewall

Compare the fitted tires with the vehicle placard and owner’s manual. Previous owners may have changed wheels or tires. Some vehicles have different front and rear sizes. Tell us about modifications and send both sizes when they differ.

When the format looks different

Tires for commercial vehicles, motorcycles or equipment can use other marking formats. Copy the full marking exactly or text a photo; you do not have to translate it into a passenger-car format. Our quote form accepts specialty sizes.