305/45R20 (original) (raw)
305/45R20
305/45R20 Tire Size in Inches and Millimeters
305/45R20 tires have a diameter of 30.8" (782 mm), a tread width of 12" (305 mm), and a wheel diameter of 20" (508 mm).The sidewall of the tire is 5.4" (137 mm), and the tire's circumference is 96.7" (2455.5 mm). This means a 305/45R20 tire will make make 655 revolutions per mile, or 407 revolutions per kilometer.
| Spec | Inches | Metric |
|---|---|---|
| Diameter | 30.8" | 782 mm |
| Width | 12" | 305 mm |
| Wheel | 20" | 508 mm |
| Sidewall | 5.4" | 137 mm |
| Circum | 96.7" | 2455.5 mm |
| Revolutions | 655 per mile | 407 per km |
What Does 305/45R20 Mean?
The tire size 305/45R20 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.
- 45: 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 45% 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.
- 20: 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 20-inch wheel.
How To Convert 305/45R20 Into Inches
The 305/45R20 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, 45, 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 0.45, which gives us approximately 5.4 inches.
Finally, the last number in the tire size, 20, represents the diameter of the wheel rim in inches. Therefore, the tire size 305/45R20 can be expressed in inches as roughly 12 inches wide, 5.4 inches tall, and designed to fit a 20-inch wheel rim.
Frequently Asked Questions About 305/45R20 Tires
How tall is a 305/45R20 tire?
A 305/45R20 tire has an approximate height, also known as the overall diameter, of 30.8 inches (782 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 305/45R20 tire?
A 305/45R20 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 305/45R20 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.