315/70R18 In Inches – Tire Size & Wheel Fitment Guide

What size tire is 315/70R18 in Inches?

The 315/70R18 tire has an overall diameter of 35.4 inches, a section width of 12.4 inches, and can be mounted on 18 x 8.0-11.0 inches rim. The equivalent tire size in the high flotation system is 35.4x12.4R18.

	Inches	Millimeters
Tire Diameter	35.4	898.2
Section Width	12.4	315
Rim Height	18	457
Sidewall Height	8.7	220.5
Circumference	111.1	2821.8

12.4"

35.4"

111.1"

18"

8.7"

570.3 Revs/Mile

To help you understand, we'll break down each part of the 315/70R18 tire size to know what these numbers represent & how they may affect your tire's performance:

How wide is a 315/70R18 tire?

The 315/70R18 tire has a width of 12.4 inches (315 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 315/70R18 tire?

The 315/70R18 tire has a height of 35.4 inches (898.2 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.

315/70R18 sidewall height

The 315/70R18 has a sidewall height of 8.7 inches (220.5 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 315/70R18 tire?

You can mount the 315/70R18 tire on a rim with a height of 18 inches and a width ranging from 8.0-11.0 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.

315/70R18 circumference

The 315/70R18 tire has a circumference of 111.1 inches (2821.8 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.

315/70R18 Revolutions

The 315/70R18 performs 570.3 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 315/70R18

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 315/70R18: