Where to find your tire size
- The sticker inside the driver's door. It lists the size your car maker chose, front and rear, and the pressure to use. This is the size to trust first.
- The side of the tire itself. Look for a code like P225/65R17 102H in raised letters. If the tires were replaced, it may differ from the door sticker.
- Your owner's manual. The tires and loading section repeats the door sticker, sometimes with the other sizes offered for your model.
Some cars list a different size front and rear, or several sizes by trim. Check yours, not a similar car.
What the numbers mean
Take 225/65R17. The tire is 225 millimetres wide. Its sidewall is 65 percent of that width (146 mm). R means radial, the build of nearly every car tire today. It fits a 17-inch wheel. Put together, the tire stands about 28.5 inches tall. The tool above does that arithmetic for any size.
Read every mark on the sidewall: load index, speed rating, date code
Thinking of a different size?
A taller or shorter tire changes what your speedometer shows. Compare two sizes side by side, with the speed you really drive when the dial says 60.