235/40R18 In Inches – Tire Size & Wheel Fitment Guide


What size tire is 235/40R18 in Inches?

The 235/40R18 tire has an overall diameter of 25.4 inches, a section width of 9.3 inches, and can be mounted on 18 x 8.0-9.5 inches rim. The equivalent tire size in the high flotation system is 25.4x9.3R18.

InchesMillimeters
Tire Diameter25.4645.2
Section Width9.3235
Rim Height18457
Sidewall Height3.794
Circumference79.82027
tire diameter
9.3"
25.4"
Tire Side
Tire Circumference
79.8"
18"
3.7"
794 Revs/Mile

To help you understand, we'll break down each part of the 235/40R18 tire size to know what these numbers represent & how they may affect your tire's performance:



How wide is a 235/40R18 tire?

The 235/40R18 tire has a width of 9.3 inches (235 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.

tread width
Tread width: 9.3 In.


How tall is a 235/40R18 tire?

The 235/40R18 tire has a height of 25.4 inches (645.2 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.

Tire Diameter
Tire diameter: 25.4 In.


235/40R18 sidewall height

The 235/40R18 has a sidewall height of 3.7 inches (94 mm). It’s measured from the rim to the outer edge of the tire's tread, expressed as a percentage of tire width.

sidewall height
Sidewall height: 3.7 In.


What size rim do you need for 235/40R18 tire?

You can mount the 235/40R18 tire on a rim with a height of 18 inches and a width ranging from 8.0-9.5 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.

Rim Diameter
Rim height: 18 In.
rim width
Rim width: 8.0-9.5 In.


235/40R18 circumference

The 235/40R18 tire has a circumference of 79.8 inches (2027 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.

Circumference
Circumference: 79.8 In.


235/40R18 Revolutions

The 235/40R18 performs 794 revs/mile. Revolutions per mile indicate the number of times a tire rotates while it covers the distance of one mile.

Revolutions
794 revs/mile


Replacement Tire Sizes for 235/40R18

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 235/40R18:

Tire SizeDiameterRim (H x W)
145/80R1726.1″ (+2.7%)17″ x n/a
165/70R1726.1″ (+2.7%)17″ x n/a
205/50R1826.1″ (+2.7%)18″ x n/a
295/35R1826.1″ (+2.7%)18″ x 10.0-11.5″
345/30R1826.1″ (+2.7%)18″ x 12.0-14.0″
225/40R1926.1″ (+2.7%)19″ x 7.5-9.0″
255/45R1726″ (+2.3%)17″ x 8.0-9.5″
285/40R1726″ (+2.3%)17″ x 9.5-11.0″
145/70R1826″ (+2.3%)18″ x n/a
185/55R1826″ (+2.3%)18″ x n/a
225/45R1826″ (+2.3%)18″ x 7.0-8.5″
255/40R1826″ (+2.3%)18″ x 8.5-10.0″
255/35R1926″ (+2.3%)19″ x 8.5-10.0″
295/30R1926″ (+2.3%)19″ x 10.0-11.0″
355/25R1926″ (+2.3%)19″ x 12.5-13.5″
255/30R2026″ (+2.3%)20″ x 8.5-9.5″
305/25R2026″ (+2.3%)20″ x 10.5-11.5″
205/55R1725.9″ (+1.9%)17″ x 5.5-7.5″
225/50R1725.9″ (+1.9%)17″ x 6.0-8.0″
285/35R1825.9″ (+1.9%)18″ x 9.5-11.0″
335/30R1825.9″ (+1.9%)18″ x 11.5-12.5″
125/70R1925.9″ (+1.9%)19″ x n/a
215/40R1925.8″ (+1.6%)19″ x n/a
245/35R1925.8″ (+1.6%)19″ x 8.0-9.5″
245/30R2025.8″ (+1.6%)20″ x 8.0-9.0″
295/25R2025.8″ (+1.6%)20″ x 10.0-11.0″
185/60R1725.7″ (+1.2%)17″ x n/a
245/45R1725.7″ (+1.2%)17″ x 7.5-9.0″
275/40R1725.7″ (+1.2%)17″ x 9.0-11.0″
315/35R1725.7″ (+1.2%)17″ x 10.5-12.5″
245/40R1825.7″ (+1.2%)18″ x 8.0-9.5″
285/30R1925.7″ (+1.2%)19″ x 9.5-10.5″
115/95R1725.6″ (+0.8%)17″ x n/a
215/45R1825.6″ (+0.8%)18″ x 7.0-8.0″
275/35R1825.6″ (+0.8%)18″ x 9.0-11.0″
335/25R1925.6″ (+0.8%)19″ x 11.5-12.5″
235/30R2025.6″ (+0.8%)20″ x 8.5″
285/25R2025.6″ (+0.8%)20″ x 10.5″
135/80R1725.5″ (+0.4%)17″ x n/a
155/70R1725.5″ (+0.4%)17″ x n/a
215/50R1725.5″ (+0.4%)17″ x 6.0-7.5″
235/35R1925.5″ (+0.4%)19″ x 8.0-9.5″
275/30R1925.5″ (+0.4%)19″ x 9.0-10.0″
195/55R1725.4″ (Equal)17″ x 5.5-7.0″
305/35R1725.4″ (Equal)17″ x n/a
135/70R1825.4″ (Equal)18″ x n/a
145/65R1825.4″ (Equal)18″ x n/a
315/30R1825.4″ (Equal)18″ x 10.5-11.5″
135/60R1925.4″ (Equal)19″ x n/a
275/25R2025.4″ (Equal)20″ x 10.0″
235/45R1725.3″ (-0.4%)17″ x 7.5-9.0″
265/40R1725.3″ (-0.4%)17″ x 9.0-10.5″
155/60R1825.3″ (-0.4%)18″ x n/a
205/45R1825.3″ (-0.4%)18″ x 6.5-7.5″
265/35R1825.3″ (-0.4%)18″ x 9.0-10.5″
115/70R1925.3″ (-0.4%)19″ x n/a
265/30R1925.3″ (-0.4%)19″ x 9.0-10.0″
225/30R2025.3″ (-0.4%)20″ x 8.0″
305/30R1825.2″ (-0.8%)18″ x 10.5-11.5″
225/35R1925.2″ (-0.8%)19″ x 7.5-9.0″
315/25R1925.2″ (-0.8%)19″ x 11.0-12.0″
205/50R1725.1″ (-1.2%)17″ x 5.5-7.5″
295/35R1725.1″ (-1.2%)17″ x n/a
225/40R1825.1″ (-1.2%)18″ x 7.5-9.0″
215/30R2025.1″ (-1.2%)20″ x 7.5-9.0″
145/70R1725″ (-1.6%)17″ x n/a
225/45R1725″ (-1.6%)17″ x 7.0-8.5″
255/40R1725″ (-1.6%)17″ x 8.5-10.0″
255/35R1825″ (-1.6%)18″ x 8.5-10.0″
295/30R1825″ (-1.6%)18″ x 10.0-11.0″
255/30R1925″ (-1.6%)19″ x 8.5-9.5″
305/25R1925″ (-1.6%)19″ x 10.5-11.5″
125/80R1724.9″ (-2%)17″ x 3.0-4.0″
285/35R1724.9″ (-2%)17″ x n/a
125/70R1824.9″ (-2%)18″ x n/a
215/35R1924.9″ (-2%)19″ x 7.0-8.5″
215/40R1824.8″ (-2.4%)18″ x 7.0-8.5″
245/35R1824.8″ (-2.4%)18″ x 8.0-9.5″
245/30R1924.8″ (-2.4%)19″ x 8.0-9.0″
295/25R1924.8″ (-2.4%)19″ x 10.0-11.0″
195/50R1724.7″ (-2.8%)17″ x n/a
245/40R1724.7″ (-2.8%)17″ x 8.0-9.5″
285/30R1824.7″ (-2.8%)18″ x 9.5-10.5″

More tire sizes for 18" Wheel:

23″ Tire Diameter

24″ Tire Diameter

25″ Tire Diameter


26″ Tire Diameter

27″ Tire Diameter

28″ Tire Diameter


29″ Tire Diameter

30″ Tire Diameter

31″ Tire Diameter


32″ Tire Diameter

33″ Tire Diameter

34″ Tire Diameter


35″ Tire Diameter

36″ Tire Diameter

38″ Tire Diameter


*Disclaimer: Please note that our tire dimensions & measurements are an approximation number, while the tire manufacturers may have different ways in calculating or rounding numbers. We recommend referring to the vehicle manufacturer's manual or checking with the tire technician to find out the correct tire size for your vehicle.


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