305/55R20 In Inches – Tire Size & Rim Fitment Guide

What size tire is 305/55R20 in Inches?

The 305/55R20 tire has an overall diameter of 33.2 inches, a section width of 12 inches, and can be mounted on 20 x 8.5-10.0 inches rim. The equivalent tire size in the high flotation system is 33.2x12R20.

	Inches	Millimeters
Tire Diameter	33.2	843.5
Section Width	12	305
Rim Height	20	508
Sidewall Height	6.6	167.8
Circumference	104.3	2649.9

12"

33.2"

104.3"

20"

6.6"

607.3 Revs/Mile

To make it clear, we'll break down each part of the 305/55R20 tire size to know what these numbers represent & how they may affect your vehicle tire's performance:

How tall is a 305/55R20 tire?

A 305/55R20 tire has a height of 33.2 inches (843.5 mm). This is the measurement from the bottom to the highest point at the top of a tire through its exact center when inflated and no load.

How wide is a 305/55R20 tire?

The 305/55R20 has a width of 12 inches (305 mm). This is the tire measurement at its thickest point, the distance between the inner sidewall’s and the outer sidewall’s widest point, also known as section width or tread width.

305/55R20 sidewall height

The sidewall height of a 305/55R20 is 6.6 inches (167.8 mm). It’s measured from the rim to the outer edge of the tire's tread, expressed as a percentage of tire width.

What size rim do I need for 305/55R20 tire?

You can put on a rim with a height of 20 inches and a rim width ranging from 8.5-10.0 inches for a 305/55R20 tire. (Based on recommendations of The Tire and Rim Association (TRA))

Putting very wide tires on narrow rims or vice versa can result in reduced performance of the tire.

305/55R20 circumference

The 305/55R20 tire has a circumference of 104.3 inches (2649.9 mm), This is the measurement of the distance the tire covers in one full rotation.

The tire circumference is important for your vehicle's overall performance, affecting its speedometer accuracy, acceleration & fuel efficiency.

305/55R20 Revolutions

The 305/55R20 performs 607.3 revs/mile. Revolutions per mile indicate the number of times a tire rotates while it covers the distance of one mile.

Alternative Tire Sizes for 305/55R20

As a rule, you can replace the tire within a 3% difference in tire diameter (height) of the OEM tire size. Here is the full list of replacement sizes compatible with 305/55R20: