255/40R20 In Inches – Tire Size & Wheel Fitment Guide

What size tire is 255/40R20 in Inches?

The 255/40R20 tire has an overall diameter of 28 inches, a section width of 10 inches, and can be mounted on 20 x 8.5-10.0 inches rim. The equivalent tire size in the high flotation system is 28x10R20.

	Inches	Millimeters
Tire Diameter	28	712
Section Width	10	255
Rim Height	20	508
Sidewall Height	4	102
Circumference	88.1	2236.8

10"

28"

88.1"

20"

4"

719.5 Revs/Mile

To help you understand, we'll break down each part of the 255/40R20 tire size to know what these numbers represent & how they may affect your tire's performance:

How wide is a 255/40R20 tire?

The 255/40R20 tire has a width of 10 inches (255 mm). This is the measurement at its thickest point, the distance between the outer sidewall and the inner sidewall’s widest point, also called as tread width or section width.

How tall is a 255/40R20 tire?

The 255/40R20 tire has a height of 28 inches (712 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 unloaded.

255/40R20 sidewall height

The 255/40R20 has a sidewall height of 4 inches (102 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 you need for 255/40R20 tire?

You can mount the 255/40R20 tire on a rim with a height of 20 inches and a width ranging from 8.5-10.0 inches. (Based on recommendations of The Tire and Rim Association (TRA))

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

255/40R20 circumference

The 255/40R20 tire has a circumference of 88.1 inches (2236.8 mm), This is the measurement of the distance the tire travels in one revolution.

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

255/40R20 Revolutions

The 255/40R20 performs 719.5 revs/mile. Revolutions per mile indicate the number of times a tire rotates while it covers the distance of one mile.

Replacement Tire Sizes for 255/40R20

As a rule, you can replace the tire within a 3% difference in tire diameter (height) of the OEM tire size. Here is a list of compatible tire sizes for 255/40R20: