When converted to inches, 255/45R21 is equivalent to 30x10R21.
255/45R21 tire has a section width of 10 inches which is the measurement of tire's width from its inner sidewall to its outer sidewall. Rim diameter of 21 inches represents the size of the wheel the tire can be mounted on. Sidewall height of 4.5 inches (115 mm) is the measurement from the wheel rim to top of the tire tread. Overall diameter of 30 inches (763 mm) reflects the outer diameter of the tire and stands for tire height. Circumference of 94.2 inches (2395.8 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. 255/45R21 tire makes 673 revolutions per mile (417 revolutions per kilometer).
Overall Diameter (Tire Height)
417 per km
673 per mile
Best Prices on 255/45R21 Tires
255/45R21 Replacement Tire Sizes
Replacement tires have to be within 3% of the original tire's overall diameter. 255/45R21 tire can be replaced with 26 compatible tire sizes. Select optional plus size to see its specs.