255/40R21 tires are 29.0″ tall, have a section width of 10.0″, and fit wheels with a diameter of 21. The circumference is 91.2″ that translates into 695 revolutions per mile. As a rule, they can be mounted on the wheels with 21″ x 8.5-10″ rim width. In the high flotation system, the equivalent tire size is 29X10R21.
What is 255/40R21 in inches?
|Tire Section Width:||10.0″|
|Rim Width Range:||21″ x 8.5-10″|
Alternate sizes – Upsizing Wheels or Tires?
What is a 255/40R21 equivalent to?
Check out the chart below to find possible alternatives to the 255/40R21 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 size||Diameter||Difference||Width||Wheel size|
What does 255/40R21 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 LT||The first letter in the string denotes the class. P stands for passenger vehicles, LT is intended for light trucks carrying heavy loads.|
|255||It means the width of the tire is 255 millimeters|
|40||The tire has an aspect ratio of 40. To put it simple, the sidewall height is 40% of the width, so it would be 4.0″.|
|R||R stands for the Radial, a standard construction method for about 99% of tires.|
|21||The tire is designed to fit 21″ x 8.5-10″ rims that are 21 inches in diameter.|
Popular questions about 255/40R21 tire size
How wide is a 255/40R21 tire?
The tires of the given size have a section width of 10.0″ inches.
How tall is a 255/40R21 tire?
The height of the following tire size equals 29.0″ inches.
What rims will fit 255/40R21 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 8.5-10″ for 255/40R21 tires.