225/45R18 tire size
A 225/45R18 tire stands 26.0 inches tall and 8.9 inches wide, with a 4.0-inch sidewall on an 18-inch rim.
- Overall height
- 26.0 in660 mm
- Section width
- 8.9 in225 mm
- Sidewall height
- 4.0 in101 mm
- Rim diameter
- 18 in457 mm
- Circumference
- 81.6 in2073 mm
- Revolutions per mile
- 777483 per km
- Inch size
- 26.0x8.9R18
Compare it with any other size in the tire size calculator.
Sizes you can swap to
These 18-inch sizes are within two width steps and 3% of a 225/45R18's overall height, the usual limit before the speedometer, ABS and transmission notice. The closest is 205/50R18, 0.4% taller (0.10 in). Wider sizes also need room in the wheel well and a rim width that suits them.
Plus and minus sizes
Changing rim size means changing the sidewall to keep the same overall height. On 16-inch or 17-inch or 19-inch or 20-inch rims, these are the closest matches to a 225/45R18.
Other 18-inch sizes near 225/45R18
225 mm wide, other sidewalls
45 series, other widths
See the other sizes for this rim on 18-inch tire sizes.
Shop 225/45R18 tires
These open each store's own list of 225/45R18 tires, where you can filter by type, load and speed rating.
225/45R18 questions
How tall is a 225/45R18 tire?
About 26.0 inches (660 mm) from the ground to the top of the tread, unloaded. On the vehicle, carrying weight, it sits a little lower.
What does 225/45R18 mean?
225 is the section width in millimetres (8.9 in). 45 means the sidewall is 45% of that width: 101 mm, or 4.0 in. R means radial construction, and 18 is the rim diameter in inches.
Can I use 245/40R18 instead of 225/45R18?
245/40R18 is 1.0% shorter (0.26 in) and 20 mm wider, which is inside the usual 3% rule. With it fitted, the speedometer shows 60 mph when you are doing 59.4 mph. Make sure the extra width clears the suspension and fender liner at full lock.
What is 225/45R18 in inches?
In inch terms it is 26.0x8.9R18: 26.0 inches tall, 8.9 inches wide, for an 18-inch rim.
How many revolutions per mile does a 225/45R18 make?
About 777 turns per mile, worked out from its unloaded circumference of 81.6 inches. Makers list slightly higher numbers for their own tires, because a loaded tire rolls on a smaller radius.