325/40R21 Tires

325/40R21 Conversion

When converted to inches, 325/40R21 is equivalent to 31.2x12.8R21.

325/40R21 tire has a section width of 12.8 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 5.1 inches (130 mm) is the measurement from the wheel rim to top of the tire tread. Overall diameter of 31.2 inches (793 mm) reflects the outer diameter of the tire and stands for tire height. Circumference of 98 inches (2490 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. 325/40R21 tire makes 647 revolutions per mile (402 revolutions per kilometer).

325/40R21 Section Width
12.8"
31.2"
325/40R21 Tire Side
Tire Circumference
98"
21"
5.1"
647 Revs/Mile
Metric Inches
Overall Diameter (Tire Height) 793 mm 31.2"
Tread Width 325 mm 12.8"
Rim Diameter 533.4 mm 21"
Sidewall Height 130 mm 5.1"
Circumference 2490 mm 98"
Revolutions 402 per km 647 per mile

325/40R21 Replacement Tire Sizes

Replacement tires have to be within 3% of the original tire's overall diameter. 325/40R21 tire can be replaced with 25 compatible tire sizes. Select optional plus size to see its specs.

Tire Size Overall Diameter Difference
265/40R22 30.4" (771 mm) -2.8%
265/45R21 30.4" (771 mm) -2.8%
305/35R22 30.4" (773 mm) -2.5%
275/40R22 30.7" (779 mm) -1.8%
315/35R22 30.7" (779 mm) -1.8%
325/30R23 30.7" (780 mm) -1.6%
275/45R21 30.7" (781 mm) -1.5%
285/35R23 30.9" (784 mm) -1.1%
315/40R21 30.9" (785 mm) -1%
325/35R22 31" (787 mm) -0.8%
285/40R22 31" (787 mm) -0.8%
255/45R22 31.1" (789 mm) -0.5%
255/50R21 31.1" (789 mm) -0.5%
285/45R21 31.1" (789 mm) -0.5%
295/35R23 31.1" (790 mm) -0.4%
295/40R22 31.3" (795 mm) 0.3%
265/45R22 31.4" (797 mm) 0.5%
305/35R23 31.4" (798 mm) 0.6%
305/40R22 31.6" (803 mm) 1.3%
275/40R23 31.7" (804 mm) 1.4%
275/45R22 31.8" (807 mm) 1.8%
275/50R21 31.9" (809 mm) 2%
285/40R23 32" (812 mm) 2.4%
325/35R23 32" (812 mm) 2.4%
285/45R22 32.1" (815 mm) 2.8%