225/40R18 tire size
225/40R18 in inches: 25.09" overall diameter — 8.86" wide, 3.54" sidewall.
Overall diameter 25.09 in 637.2 mm
Section width 8.86 in 225 mm
Sidewall height 3.54 in 90 mm
Revs / mile 804 speedo calibration
Full dimensions
| Measurement | Metric | Imperial |
|---|---|---|
| Overall diameter | 637.2 mm | 25.09 in |
| Section width | 225 mm | 8.86 in |
| Sidewall height | 90 mm | 3.54 in |
| Rim diameter | 457.2 mm | 18 in |
| Circumference | 2001.8 mm | 78.81 in |
| Revolutions per mile | 803.9 | |
| Aspect ratio | 40% | |
Compare 225/40R18 to similar sizes
Frequently asked questions
What is the overall diameter of a 225/40R18 tire?
A 225/40R18 tire has an overall diameter of 25.09 inches (637.2 mm).
How tall is a 225/40R18 tire?
The sidewall height is 90 mm (3.54 inches), and the overall diameter from the ground to the top of the tire is 25.09 inches.
How many revolutions per mile does a 225/40R18 tire make?
A 225/40R18 tire makes approximately 804 revolutions per mile. Your speedometer is calibrated to this number.
What rim size does a 225/40R18 tire fit?
A 225/40R18 tire is designed for a 18-inch rim (457.2 mm).
All dimensions calculated using standard ETRTO formulas. Always confirm fitment with your vehicle's door-placard and a qualified tire professional before purchasing.