225/40R18 in Inches

A 225/40R18 tire has a 25.1-inch diameter, a 8.9-inch width, and is designed for a 18-inch rim.

In high flotation terms, this tire is labeled as 25.1x8.9R18.

225/40R18 Tire Size
8.9"
25.1"
225/40R18 Tire Size in Inches
225/40R18 Tire Circumference
78.8"
18"
3.5"
803.9 revs/mile

225/40R18 Tire Overview

Height
25.1 inches
Wheel Diameter
18 inches
Tire Width
8.9 inches
Circumference
78.8 inches
Sidewall Height
3.5 inches
Revolutions
803.9 per mile
Tirelib.com

What does 225/40R18 mean?

225/40R18 tire size meaning in inches

225/40R18 is a tire size with the following dimensions:

  • 225 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.
  • 40 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.
  • 18 is the diameter of the wheel in inches, on which the tire is to be mounted.

225/40R18 Tire Conversion

DimensionsInchesMillimeters
Tire Diameter25.1 in637.2 mm
Section Width8.9 in225 mm
Rim Height18 in457 mm
Sidewall Height3.5 in90 mm
Circumference78.8 in2001.8 mm
Revolutions803.9 revs/mile
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FAQ About 225/40R18 Tire

How tall is a 225/40R18 tire?

The height (or diameter) of a 225/40R18 tire is 25.1 inches

How wide is a 225/40R18 tire?

The width of a 225/40R18 tire is 225 mm, which is about 8.9 inches.

What size rim fits a 225/40R18 tire?

A 225/40R18 tire fits on a rim that is 18 inches in diameter.

What does the 40 in a 225/40R18 tire mean?

The 40 in a 225/40R18 tire refers to the aspect ratio, meaning the height of the tire's sidewall is 40% of its width.


Alternative Tire Sizes for 225/40R18

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 225/40R18:

Tire SizeDiameterRim
125/70R1824.9″ (-0.8%)18 x n/a
135/60R1824.4″ (-2.8%)18 x n/a
135/70R1825.4″ (1.2%)18 x n/a
145/65R1825.4″ (1.2%)18 x n/a
155/60R1825.3″ (0.8%)18 x n/a
205/40R1824.5″ (-2.4%)18 x 7.0-8.0
205/45R1825.3″ (0.8%)18 x 6.5-7.5
215/40R1824.8″ (-1.2%)18 x 7.0-8.5
215/45R1825.6″ (2.0%)18 x 7.0-8.0
235/35R1824.5″ (-2.4%)18 x 8.0-9.5
235/40R1825.4″ (1.2%)18 x 8.0-9.5
245/35R1824.8″ (-1.2%)18 x 8.0-9.5
245/40R1825.7″ (2.4%)18 x 8.0-9.5
255/35R1825.0″ (-0.4%)18 x 8.5-10.0
265/35R1825.3″ (0.8%)18 x 9.0-10.5
275/35R1825.6″ (2.0%)18 x 9.0-11.0
285/30R1824.7″ (-1.6%)18 x 9.5-10.5
295/30R1825.0″ (-0.4%)18 x 10.0-11.0
305/30R1825.2″ (0.4%)18 x 10.5-11.5
315/30R1825.4″ (1.2%)18 x 10.5-11.5