315/30R21 tire size in inches

315/30R21 tires are 28.4″ tall, have a section width of 12.4″, and fit wheels with a diameter of 21. The circumference is 89.3″ that translates into 709 revolutions per mile. As a rule, they can be mounted on the wheels with 21″ x 10.5-11.5″ rim width. In the high flotation system, the equivalent tire size is 28.4X12.4R21.

What is 315/30R21 in inches?

Tire Diameter:28.4″
Tire Section Width:12.4″
Rim Width Range:21″ x 10.5-11.5″
Sidewall Height:3.7″

Alternate sizes – Upsizing Wheels or Tires?

What is a 315/30R21 equivalent to?

Check out the chart below to find possible alternatives to the 315/30R21 tire size staying within the 3%-range of the tire diameter, allowing to choose wider wheels or tires with smaller sidewalls. A good rule of thumb is to avoid decreasing the diameter of the wheel. If you are not sure about the custom sizes, consult the experts or stick to the factory tire size.

Tire sizeDiameterDifferenceWidthWheel size
Upsizing chart

What does 315/30R21 mean?

Trying to decode the size of the tires? Scroll down the page to learn what all these numbers on the sidewall stand for.

P or LTThe first letter in the string denotes the class. P stands for passenger vehicles, LT is intended for light trucks carrying heavy loads.
315It means the width of the tire is 315 millimeters
30The tire has an aspect ratio of 30. To put it simple, the sidewall height is 30% of the width, so it would be 3.7″.
RR stands for the Radial, a standard construction method for about 99% of tires.
21The tire is designed to fit 21″ x 10.5-11.5″ rims that are 21 inches in diameter.

Popular questions about 315/30R21 tire size

How wide is a 315/30R21 tire?

The tires of the given size have a section width of 12.4″ inches.

How tall is a 315/30R21 tire?

The height of the following tire size equals 28.4″ inches.

What rims will fit 315/30R21 tires?

For each tire size, often there are several wheel sizes. You can’t put very wide tires on narrow rims or vise versa. You need the rim size of 21″ x 10.5-11.5″ for 315/30R21 tires.

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