What does 305/25R21 mean?
305/25R21 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.
- 25 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.
- 21 is the diameter of the wheel in inches, on which the tire is to be mounted.
305/25R21 Tire Conversion
Dimensions | Inches | Millimeters |
Tire Diameter | 27 in | 685.9 mm |
Section Width | 12 in | 305 mm |
Rim Height | 21 in | 533 mm |
Sidewall Height | 3 in | 76.3 mm |
Circumference | 84.8 in | 2154.8 mm |
Revolutions | 746.9 revs/mile |
FAQ About 305/25R21 Tire
How tall is a 305/25R21 tire?
The height (or diameter) of a 305/25R21 tire is 27 inches
How wide is a 305/25R21 tire?
The width of a 305/25R21 tire is 305 mm, which is about 12 inches.
What size rim fits a 305/25R21 tire?
A 305/25R21 tire fits on a rim that is 21 inches in diameter.
What does the 25 in a 305/25R21 tire mean?
The 25 in a 305/25R21 tire refers to the aspect ratio, meaning the height of the tire's sidewall is 25% of its width.
Alternative Tire Sizes for 305/25R21
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 305/25R21:
Tire Size | Diameter | Rim |
---|---|---|
255/30R21 | 27.0″ (Equal) | 21 x 8.5-9.5 |
235/30R21 | 26.6″ (-1.5%) | 21 x n/a |
235/35R21 | 27.5″ (1.9%) | 21 x n/a |
245/30R21 | 26.8″ (-0.7%) | 21 x 8.0-9.0 |
245/35R21 | 27.8″ (3.0%) | 21 x 8.0-9.0 |
265/30R21 | 27.3″ (1.1%) | 21 x 9.0-10.0 |
275/25R21 | 26.4″ (-2.2%) | 21 x 10 |
275/30R21 | 27.5″ (1.9%) | 21 x 9.0-10.0 |
285/30R21 | 27.7″ (2.6%) | 21 x 9.5-10.5 |
295/25R21 | 26.8″ (-0.7%) | 21 x 10.0-11.0 |
325/25R21 | 27.4″ (1.5%) | 21 x 11.5-12.5 |
375/20R21 | 26.9″ (-0.4%) | 21 x n/a |