305/45R20 in Inches

A 305/45R20 tire has a 30.8-inch diameter, a 12-inch width, and is designed for a 20-inch rim.

In high flotation terms, this tire is labeled as 30.8x12R20.

305/45R20 Tire Size
12"
30.8"
305/45R20 Tire Size in Inches
305/45R20 Tire Circumference
96.8"
20"
5.4"
654.7 revs/mile

305/45R20 Tire Overview

Height
30.8 inches
Wheel Diameter
20 inches
Tire Width
12 inches
Circumference
96.8 inches
Sidewall Height
5.4 inches
Revolutions
654.7 per mile
Tirelib.com

What does 305/45R20 mean?

305/45R20 tire size meaning in inches

305/45R20 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.
  • 45 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.

305/45R20 Tire Conversion

DimensionsInchesMillimeters
Tire Diameter30.8 in782.5 mm
Section Width12 in305 mm
Rim Height20 in508 mm
Sidewall Height5.4 in137.3 mm
Circumference96.8 in2458.3 mm
Revolutions654.7 revs/mile
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FAQ About 305/45R20 Tire

How tall is a 305/45R20 tire?

The height (or diameter) of a 305/45R20 tire is 30.8 inches

How wide is a 305/45R20 tire?

The width of a 305/45R20 tire is 305 mm, which is about 12 inches.

What size rim fits a 305/45R20 tire?

A 305/45R20 tire fits on a rim that is 20 inches in diameter.

What does the 45 in a 305/45R20 tire mean?

The 45 in a 305/45R20 tire refers to the aspect ratio, meaning the height of the tire's sidewall is 45% of its width.

Alternative Tire Sizes for 305/45R20

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 305/45R20:

Tire SizeDiameterRim
275/50R2030.8″ (Equal)20 x 7.5-9.5
235/55R2030.2″ (-1.9%)20 x 6.5-8.5
235/60R2031.1″ (1.0%)20 x 6.5-8.5
245/60R2031.6″ (2.6%)20 x 7.0-8.5
255/50R2030.0″ (-2.6%)20 x 7.0-9.0
255/55R2031.0″ (0.6%)20 x 7.0-9.0
265/50R2030.4″ (-1.3%)20 x 7.5-9.5
265/55R2031.5″ (2.3%)20 x n/a
285/45R2030.1″ (-2.3%)20 x 9.0-10.5
285/50R2031.2″ (1.3%)20 x 8.0-10.0
295/45R2030.5″ (-1.0%)20 x 9.5-11.0
295/50R2031.6″ (2.6%)20 x 8.0-10.5