245/40R18 tire size
A 245/40R18 tire is 245 mm wide with a sidewall 40% of its width (98.0 mm), fits a 18-inch rim and has an overall diameter of 653 mm (25.7 in).
| Dimension | Metric | Imperial |
|---|---|---|
| Section width | 245 mm | 9.65 in |
| Sidewall height | 98.0 mm | 3.86 in |
| Rim diameter | 457.2 mm | 18 in |
| Overall diameter | 653.2 mm | 25.72 in |
| Circumference | 2,052.1 mm | 80.79 in |
| Revolutions | 487 per km | 784 per mile |
Reading the size 245/40R18
245Width in mm40Aspect ratio (sidewall % of width)RRadial construction18Rim diameter in inches
The load index and speed rating (for example 91V) follow the size on the sidewall. Replacement tires should match or exceed the original load index and speed rating.
Alternative sizes within 3% of 245/40R18
A replacement size should stay within about 3% of the original diameter so the speedometer, ABS and transmission stay accurate. Always check clearance, load index and the vehicle manufacturer's approved sizes.
Compare 245/40R18 with any size →