What does 305/40R18 mean?
305/40R18 is a tire size with the following dimensions:
- 305 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.
- 18 is the diameter of the wheel in inches, on which the tire is to be mounted.
305/40R18 Tire Conversion
Dimensions | Inches | Millimeters |
Tire Diameter | 27.6 in | 701.2 mm |
Section Width | 12 in | 305 mm |
Rim Height | 18 in | 457 mm |
Sidewall Height | 4.8 in | 122 mm |
Circumference | 86.7 in | 2202.9 mm |
Revolutions | 730.6 revs/mile |
FAQ About 305/40R18 Tire
How tall is a 305/40R18 tire?
The height (or diameter) of a 305/40R18 tire is 27.6 inches
How wide is a 305/40R18 tire?
The width of a 305/40R18 tire is 305 mm, which is about 12 inches.
What size rim fits a 305/40R18 tire?
A 305/40R18 tire fits on a rim that is 18 inches in diameter.
What does the 40 in a 305/40R18 tire mean?
The 40 in a 305/40R18 tire refers to the aspect ratio, meaning the height of the tire's sidewall is 40% of its width.
Alternative Tire Sizes for 305/40R18
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 305/40R18:
Tire Size | Diameter | Rim |
---|---|---|
245/50R18 | 27.6″ (Equal) | 18 x 7.0-8.5 |
145/80R18 | 27.1″ (-1.8%) | 18 x n/a |
145/85R18 | 27.7″ (0.4%) | 18 x n/a |
155/80R18 | 27.8″ (0.7%) | 18 x n/a |
155/85R18 | 28.4″ (2.9%) | 18 x n/a |
165/70R18 | 27.1″ (-1.8%) | 18 x n/a |
205/55R18 | 26.9″ (-2.5%) | 18 x 5.5-7.5 |
205/60R18 | 27.7″ (0.4%) | 18 x 5.0-7.5 |
215/55R18 | 27.3″ (-1.1%) | 18 x 6.0-7.5 |
225/50R18 | 26.9″ (-2.5%) | 18 x 6.0-8.0 |
225/55R18 | 27.7″ (0.4%) | 18 x 6.0-8.0 |
235/50R18 | 27.3″ (-1.1%) | 18 x 6.5-8.5 |
235/55R18 | 28.2″ (2.2%) | 18 x 6.5-8.5 |
255/45R18 | 27.0″ (-2.2%) | 18 x 8.0-9.5 |
255/50R18 | 28.0″ (1.4%) | 18 x 7.0-9.0 |
265/45R18 | 27.4″ (-0.7%) | 18 x 8.5-10.0 |
265/50R18 | 28.4″ (2.9%) | 18 x 7.5-9.5 |
275/45R18 | 27.7″ (0.4%) | 18 x 8.5-10.5 |
285/40R18 | 27.0″ (-2.2%) | 18 x 9.5-11.0 |
285/45R18 | 28.1″ (1.8%) | 18 x 9.0-10.5 |
295/40R18 | 27.3″ (-1.1%) | 18 x 10.0-11.5 |
315/40R18 | 27.9″ (1.1%) | 18 x 10.5-12.5 |
325/35R18 | 27.0″ (-2.2%) | 18 x 11.0-13.0 |
335/35R18 | 27.2″ (-1.4%) | 18 x n/a |
345/35R18 | 27.5″ (-0.4%) | 18 x 11.5-13.5 |