What does 255/40R20 mean?
255/40R20 is a tire size with the following dimensions:
- 255 is the width of the tire in millimeters. This number also indicates the appropriate width of the rim on which the tire should be mounted.
- 40 is the aspect ratio, which is the ratio of the tire's height to its width. This affects the tire's handling and ride comfort
- R indicates the tire's construction type, meaning it has a radial construction. This provides stability and precision to the tire.
- 20 is the diameter of the wheel in inches, on which the tire is to be mounted.
255/40R20 Tire Conversion
| Dimensions | Inches | Millimeters |
| Tire Diameter | 28 in | 712 mm |
| Section Width | 10 in | 255 mm |
| Rim Height | 20 in | 508 mm |
| Sidewall Height | 4 in | 102 mm |
| Circumference | 88.1 in | 2236.8 mm |
| Revolutions | 719.5 revs/mile | |
Not the tire size you are searching for? Try our Tire Size Calculator.
FAQ About 255/40R20 Tire
How tall is a 255/40R20 tire?
The height (or diameter) of a 255/40R20 tire is 28 inches
How wide is a 255/40R20 tire?
The width of a 255/40R20 tire is 255 mm, which is about 10 inches.
What size rim fits a 255/40R20 tire?
A 255/40R20 tire fits on a rim that is 20 inches in diameter.
What does the 40 in a 255/40R20 tire mean?
The 40 in a 255/40R20 tire refers to the aspect ratio, meaning the height of the tire's sidewall is 40% of its width.
Alternative Tire Sizes for 255/40R20
Typically, it's recommended to choose a tire with a diameter (height) within 3% of the original equipment manufacturer (OEM) tire size.
However, keep in mind that this is a general guideline and not an absolute rule.
Here are some tire sizes that are compatible with the 255/40R20:
| Tire Size | Diameter | Rim |
|---|---|---|
| 225/45R20 | 28.0″ (Equal) | 20 x 8.0-9.5 |
| 145/65R20 | 27.4″ (-2.1%) | 20 x n/a |
| 155/60R20 | 27.3″ (-2.5%) | 20 x 4.5-5.5 |
| 155/65R20 | 27.9″ (-0.4%) | 20 x n/a |
| 165/60R20 | 27.8″ (-0.7%) | 20 x n/a |
| 175/55R20 | 27.6″ (-1.4%) | 20 x 5.0-6.0 |
| 195/50R20 | 27.7″ (-1.1%) | 20 x 5.5-7.0 |
| 215/45R20 | 27.6″ (-1.4%) | 20 x 7.0-8.0 |
| 235/40R20 | 27.4″ (-2.1%) | 20 x 8.0-9.5 |
| 235/45R20 | 28.3″ (1.1%) | 20 x 7.5-9.0 |
| 245/40R20 | 27.7″ (-1.1%) | 20 x 8.0-9.5 |
| 245/45R20 | 28.7″ (2.5%) | 20 x 7.5-9.0 |
| 265/35R20 | 27.3″ (-2.5%) | 20 x 9.0-10.5 |
| 265/40R20 | 28.3″ (1.1%) | 20 x 9.0-10.5 |
| 275/35R20 | 27.6″ (-1.4%) | 20 x 9.0-11.0 |
| 275/40R20 | 28.7″ (2.5%) | 20 x 9.0-11.0 |
| 285/35R20 | 27.9″ (-0.4%) | 20 x 9.5-11.0 |
| 295/35R20 | 28.1″ (0.4%) | 20 x 10.0-11.5 |
| 305/30R20 | 27.2″ (-2.9%) | 20 x 10.5-11.5 |
| 305/35R20 | 28.4″ (1.4%) | 20 x 10.0-12.0 |
| 315/30R20 | 27.4″ (-2.1%) | 20 x 10.5-11.5 |
| 315/35R20 | 28.7″ (2.5%) | 20 x 10.5-12.5 |
| 325/30R20 | 27.7″ (-1.1%) | 20 x 11.0-12.0 |
| 335/30R20 | 27.9″ (-0.4%) | 20 x 11.5-12.5 |
| 345/30R20 | 28.1″ (0.4%) | 20 x 12.0-13.0 |