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FIRESTONE COMPLETE AUTO CARE HAS PUT TIRES ON MORE CARS THAN ANY OTHER COMPANY.
21 Inch Tires
Browse 21 Inch Tires
While 21-inch tires aren't the most popular size for most vehicles, there are some make and models that call for them—and Firestone Complete Auto Care can help make sure you get the right tires for you. Browse our versatile all-season tires, reliable 21-inch all-terrain tires, tough winter tires, and even some that can help improve your fuel efficiency. Firestone Complete Auto Care can help you navigate your options and choose the right 21-inch tires for you based on your budget and driving habits. All 21-inch tires are sorted by tire width, height, and diameter. Explore the tires we have to offer for your vehicle below.
What's My 21 Inch Tire Width?
If you need to know the width (or cross section) of your 21-inch tires, look for a series of number similar to: P275/45 R21. This number should be on the vehicle's tire information placard on the inside of the driver's side door or printed on the sidewalls of your current tires. The width of your tires in millimeters (mm) will be the first number in the series. In this example, the tire's width would be 275mm.
How to Find the Height of 21 Inch Tires
You can find the height (or aspect ratio) of your tires in the same series of numbers as the width, found either on the inside of your driver's side door or on the sidewalls of your current tires. In the example P275/45 R21, the number directly after the / refers to the height of your tires, which means the height would be 45.
The aspect ratio (height) is given as a percentage of the tire's width. It is measured from the wheel rim to the top of the tread. In the example above, the 21-inch tires would be 45% as high as they are wide. 45% of 275mm is 110mm. Converted to inches, the height of this 21-inch tire is 4.33 inches. The height is measured from the wheel rim to the top of the tread.