How to Read a Tire Size (e.g. 225/65R17 102H)

How to read a tire size

It's moulded into the sidewall, like 225/65R17 102H. Here's what each piece means.

Tap a part to highlight it

P, LT and no letter at all

Some sizes start with a letter. P (P225/65R17) is a passenger tire; no letter is also a passenger tire, just labelled the European way. LT (LT265/70R17) is a light-truck tire with stiffer construction for heavy loads and towing. LT tires show their load rating differently, as two numbers plus a load range, for example LT265/70R17 121/118S Load Range E.

Turning it into inches

Height = wheel size + two sidewalls. For 225/65R17 that's 17 + 5.8 + 5.8 = 28.5 inches. It's also why a 285/70R17 gets called a "33-inch tire": it works out to 32.7 inches.

Off-road sizes in inches

Some truck tires skip the metric format: 33x12.50R15 is 33 inches tall, 12.5 inches wide, for a 15-inch wheel.

How old are my tires?

Look for the letters DOT on the sidewall, followed by a string of letters and numbers. The last four digits are the week and year it was made: 2321 means week 23 of 2021. Older tires harden and crack even with plenty of tread left.

Last 4 digits of the DOT code

Made in week 23 of 2021 (around June 2021), so about 5 years old.