When converted to inches, 315/40R18 is equivalent to 27.9x12.4R18.
315/40R18 tire has a section width of 12.4 inches which is the measurement of tire's width from its inner sidewall to its outer sidewall. Rim diameter of 18 inches represents the size of the wheel the tire can be mounted on. Sidewall height of 5 inches (126 mm) is the measurement from the wheel rim to top of the tire tread. Overall diameter of 27.9 inches (709 mm) reflects the outer diameter of the tire and stands for tire height. Circumference of 87.6 inches (2226.3 mm) is the outer perimeter of the tire. Tire revolutions indicate the number of times a tire revolves while it covers the distance in miles or kilometers. 315/40R18 tire makes 723 revolutions per mile (449 revolutions per kilometer).
Overall Diameter (Tire Height)
449 per km
723 per mile
Best Prices on 315/40R18 Tires
315/40R18 Replacement Tire Sizes
Replacement tires have to be within 3% of the original tire's overall diameter. 315/40R18 tire can be replaced with 68 compatible tire sizes. Select optional plus size to see its specs.