305/65R18 (original) (raw)
305/65R18
305/65R18 Tire Size in Inches and Millimeters
305/65R18 tires have a diameter of 33.6" (853 mm), a tread width of 12" (305 mm), and a wheel diameter of 18" (457.2 mm).The sidewall of the tire is 7.8" (198 mm), and the tire's circumference is 105.5" (2678.4 mm). This means a 305/65R18 tire will make make 601 revolutions per mile, or 373 revolutions per kilometer.
| Spec | Inches | Metric |
|---|---|---|
| Diameter | 33.6" | 853 mm |
| Width | 12" | 305 mm |
| Wheel | 18" | 457.2 mm |
| Sidewall | 7.8" | 198 mm |
| Circum | 105.5" | 2678.4 mm |
| Revolutions | 601 per mile | 373 per km |
What Does 305/65R18 Mean?
The tire size 305/65R18 is a common size used on many trucks, SUVs, and other larger vehicles.
Here is what each part of the size designation represents:
- 305: This number represents the width of the tire in millimeters. In this case, the tire is 305 millimeters wide.
- 65: This number represents the aspect ratio of the tire, which is the height of the tire's sidewall as a percentage of its width. In this case, the sidewall height is 65% of the tire's width.
- R: This letter indicates the tire's construction type. “R” stands for radial construction, which is the most common type of tire construction today.
- 18: This number represents the diameter of the wheel that the tire is designed to fit on, in inches. In this case, the tire is designed to fit on a 18-inch wheel.
How To Convert 305/65R18 Into Inches
The 305/65R18 conversion is fairly simple. The first number in the tire size, 305, represents the width of the tire in millimeters. To convert this to inches, we divide 305 by 25.4 (since there are 25.4 millimeters in an inch). This gives us approximately 12 inches.
The second number in the tire size, 65, represents the aspect ratio or the height of the tire as a percentage of its width. To calculate the height in inches, we multiply 12 by 0.65, which gives us approximately 7.8 inches.
Finally, the last number in the tire size, 18, represents the diameter of the wheel rim in inches. Therefore, the tire size 305/65R18 can be expressed in inches as roughly 12 inches wide, 7.8 inches tall, and designed to fit a 18-inch wheel rim.
Frequently Asked Questions About 305/65R18 Tires
How tall is a 305/65R18 tire?
A 305/65R18 tire has an approximate height, also known as the overall diameter, of 33.6 inches (853 mm). This height can vary slightly depending on the brand and model of the tire, as well as the amount of air pressure in the tire.
How wide is a 305/65R18 tire?
A 305/65R18 tire has a width of approximately 12 inches (305 millimeters). The width of the tire is the first number in the tire size designation, which in this case is “305”. It’s important to note that the actual width of the tire may vary slightly depending on the brand and model of the tire, and the width may also be affected by the amount of air pressure in the tire.
Alternate 305/65R18 Replacement Tire Sizes
Upsizing your wheels or tires? Replacement tires must be within 3% of the diametor of the original tire. The following sizes fall within that range - click on any size to see detailed info about that tire and wheel combination.