255/45R20 In Inches – Tire Size & Rim Fitment Guide

What size tire is 255/45R20 in Inches?

The 255/45R20 tire has an overall diameter of 29 inches, a section width of 10 inches, and can be mounted on 20 x 8.0-9.5 inches rim. The equivalent tire size in the high flotation system is 29x10R20.

	Inches	Millimeters
Tire Diameter	29	737.5
Section Width	10	255
Rim Height	20	508
Sidewall Height	4.5	114.8
Circumference	91.2	2316.9

10"

29"

91.2"

20"

4.5"

694.6 Revs/Mile

To make it clear, we'll break down each part of the 255/45R20 tire size to know what these numbers represent & how they may affect your vehicle tire's performance:

How tall is a 255/45R20 tire?

A 255/45R20 tire has a height of 29 inches (737.5 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 255/45R20 tire?

The 255/45R20 has a width of 10 inches (255 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.

255/45R20 sidewall height

The sidewall height of a 255/45R20 is 4.5 inches (114.8 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 255/45R20 tire?

You can put on a rim with a height of 20 inches and a rim width ranging from 8.0-9.5 inches for a 255/45R20 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.

255/45R20 circumference

The 255/45R20 tire has a circumference of 91.2 inches (2316.9 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.

255/45R20 Revolutions

The 255/45R20 performs 694.6 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 255/45R20

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 255/45R20: