305/40R18 In Inches – Tire Size & Rim Fitment Guide


What size tire is 305/40R18 in Inches?

The 305/40R18 tire has an overall diameter of 27.6 inches, a section width of 12 inches, and can be mounted on 18 x 10.0-12.0 inches rim. The equivalent tire size in the high flotation system is 27.6x12R18.

InchesMillimeters
Tire Diameter27.6701.2
Section Width12305
Rim Height18457
Sidewall Height4.8122
Circumference86.72202.9
tire diameter
12"
27.6"
Tire Side
Tire Circumference
86.7"
18"
4.8"
730.6 Revs/Mile

To easy understanding, let us break down each component of the 305/40R18 tire size to know what these numbers represent and how they may affect your vehicle's performance:


How tall is a 305/40R18 tire?

A 305/40R18 tire has a height of 27.6 inches (701.2 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 no load.

Tire Diameter
Tire diameter: 27.6 In.

How wide is a 305/40R18 tire?

The 305/40R18 has a width of 12 inches (305 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.

tread width
Tread width: 12 In.

305/40R18 sidewall height

The sidewall height of a 305/40R18 is 4.8 inches (122 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: 4.8 In.

What size rim do I need for 305/40R18 tire?

You can put on a rim with a height of 18 inches and a rim width ranging from 10.0-12.0 inches for a 305/40R18 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.

Rim Diameter
Rim height: 18 In.
rim width
Rim width: 10.0-12.0 In.

305/40R18 circumference

The 305/40R18 tire has a circumference of 86.7 inches (2202.9 mm), This is the measurement of the distance the tire covers in one full rotation.

The tire circumference plays a crucial role in your vehicle's overall performance, affecting its speedometer accuracy, acceleration and fuel efficiency.

Circumference
Circumference: 86.7 In.

305/40R18 Revolutions

The 305/40R18 performs 730.6 revs/mile. Revolutions per mile indicate the number of times a tire rotates while it covers the distance of one mile.

Revolutions
730.6 revs/mile

Alternative Tire Sizes for 305/40R18

As a rule, you can replace the tire within a 3% difference in tire diameter (height) of the OEM tire size. However, it should be considered as a general guideline, not a hard and fast rule. Here is a list of compatible tire sizes for 305/40R18:

Tire SizeDiameterRim (H x W)
155/85R1828.4″ (+2.8%)18″ x n/a
265/50R1828.4″ (+2.8%)18″ x 7.5-9.5″
265/45R1928.4″ (+2.8%)19″ x 8.5-10.0″
305/35R2028.4″ (+2.8%)20″ x 10.0-12.0″
315/30R2128.4″ (+2.8%)21″ x 10.5-11.5″
235/50R1928.3″ (+2.5%)19″ x 6.5-8.5″
295/40R1928.3″ (+2.5%)19″ x 10.0-11.5″
235/45R2028.3″ (+2.5%)20″ x 7.5-9.0″
265/40R2028.3″ (+2.5%)20″ x 9.0-10.5″
265/35R2128.3″ (+2.5%)21″ x 9.0-10.5″
315/45R1728.2″ (+2.1%)17″ x 10.0-12.0″
235/55R1828.2″ (+2.1%)18″ x 6.5-8.5″
305/30R2128.2″ (+2.1%)21″ x 10.5-11.5″
235/60R1728.1″ (+1.8%)17″ x 6.5-8.5″
285/45R1828.1″ (+1.8%)18″ x 9.0-10.5″
145/80R1928.1″ (+1.8%)19″ x n/a
295/35R2028.1″ (+1.8%)20″ x 10.0-11.5″
345/30R2028.1″ (+1.8%)20″ x 12.0-13.0″
155/90R1728″ (+1.4%)17″ x n/a
215/65R1728″ (+1.4%)17″ x 6.0-7.5″
255/55R1728″ (+1.4%)17″ x 7.0-9.0″
255/50R1828″ (+1.4%)18″ x 7.0-9.0″
255/45R1928″ (+1.4%)19″ x 8.0-9.5″
285/40R1928″ (+1.4%)19″ x 9.5-11.0″
225/45R2028″ (+1.4%)20″ x 8.0-9.5″
255/40R2028″ (+1.4%)20″ x 8.5-10.0″
255/35R2128″ (+1.4%)21″ x 8.5-10.0″
295/30R2128″ (+1.4%)21″ x 10.0-11.0″
355/25R2128″ (+1.4%)21″ x 12.5-13.5″
345/40R1727.9″ (+1.1%)17″ x 11.5-13.5″
315/40R1827.9″ (+1.1%)18″ x 10.5-12.5″
155/65R2027.9″ (+1.1%)20″ x n/a
285/35R2027.9″ (+1.1%)20″ x 9.5-11.0″
335/30R2027.9″ (+1.1%)20″ x 11.5-12.5″
275/50R1727.8″ (+0.7%)17″ x 7.5-9.5″
305/45R1727.8″ (+0.7%)17″ x 9.5-11.5″
155/80R1827.8″ (+0.7%)18″ x n/a
165/60R2027.8″ (+0.7%)20″ x n/a
245/35R2127.8″ (+0.7%)21″ x 8.0-9.5″
245/35R2127.8″ (+0.7%)21″ x 8.0-9.0″
145/85R1827.7″ (+0.4%)18″ x n/a
205/60R1827.7″ (+0.4%)18″ x 5.0-7.5″
225/55R1827.7″ (+0.4%)18″ x 6.0-8.0″
275/45R1827.7″ (+0.4%)18″ x 8.5-10.5″
245/45R1927.7″ (+0.4%)19″ x 7.5-9.0″
275/40R1927.7″ (+0.4%)19″ x 9.0-11.0″
315/35R1927.7″ (+0.4%)19″ x n/a
195/50R2027.7″ (+0.4%)20″ x 5.5-7.0″
245/40R2027.7″ (+0.4%)20″ x 8.0-9.5″
325/30R2027.7″ (+0.4%)20″ x 11.0-12.0″
285/30R2127.7″ (+0.4%)21″ x 9.5-10.5″
225/60R1727.6″ (Equal)17″ x 6.0-8.0″
245/55R1727.6″ (Equal)17″ x 7.0-8.5″
245/50R1827.6″ (Equal)18″ x 7.0-8.5″
175/55R2027.6″ (Equal)20″ x 5.0-6.0″
215/45R2027.6″ (Equal)20″ x 7.0-8.0″
275/35R2027.6″ (Equal)20″ x 9.0-11.0″
205/65R1727.5″ (-0.4%)17″ x 5.5-7.5″
295/45R1727.5″ (-0.4%)17″ x n/a
345/35R1827.5″ (-0.4%)18″ x 11.5-13.5″
155/70R1927.5″ (-0.4%)19″ x 4.0-5.0″
215/50R1927.5″ (-0.4%)19″ x 6.0-7.5″
235/35R2127.5″ (-0.4%)21″ x n/a
275/30R2127.5″ (-0.4%)21″ x 9.0-10.0″
165/80R1727.4″ (-0.7%)17″ x n/a
265/45R1827.4″ (-0.7%)18″ x 8.5-10.0″
305/35R1927.4″ (-0.7%)19″ x 10.0-12.0″
355/30R1927.4″ (-0.7%)19″ x 12.0-13.0″
145/65R2027.4″ (-0.7%)20″ x n/a
235/40R2027.4″ (-0.7%)20″ x 8.0-9.5″
315/30R2027.4″ (-0.7%)20″ x 10.5-11.5″
325/25R2127.4″ (-0.7%)21″ x 11.5-12.5″
145/90R1727.3″ (-1.1%)17″ x n/a
215/55R1827.3″ (-1.1%)18″ x 6.0-7.5″
235/50R1827.3″ (-1.1%)18″ x 6.5-8.5″
295/40R1827.3″ (-1.1%)18″ x 10.0-11.5″
175/60R1927.3″ (-1.1%)19″ x 5.0-6.0″
235/45R1927.3″ (-1.1%)19″ x 7.5-9.0″
265/40R1927.3″ (-1.1%)19″ x 9.0-10.5″
155/60R2027.3″ (-1.1%)20″ x 4.5-5.5″
265/35R2027.3″ (-1.1%)20″ x 9.0-10.5″
265/30R2127.3″ (-1.1%)21″ x 9.0-10.0″
215/60R1727.2″ (-1.5%)17″ x 6.0-7.5″
235/55R1727.2″ (-1.5%)17″ x 6.5-8.5″
335/35R1827.2″ (-1.5%)18″ x n/a
305/30R2027.2″ (-1.5%)20″ x 10.5-11.5″
145/80R1827.1″ (-1.8%)18″ x n/a
165/70R1827.1″ (-1.8%)18″ x n/a
295/35R1927.1″ (-1.8%)19″ x 10.0-11.5″
345/30R1927.1″ (-1.8%)19″ x 11.5-12.5″
225/40R2027.1″ (-1.8%)20″ x 7.5-9.0″
255/50R1727″ (-2.2%)17″ x 7.0-9.0″
255/45R1827″ (-2.2%)18″ x 8.0-9.5″
285/40R1827″ (-2.2%)18″ x 9.5-11.0″
325/35R1827″ (-2.2%)18″ x 11.0-13.0″
225/45R1927″ (-2.2%)19″ x 7.0-8.5″
255/40R1927″ (-2.2%)19″ x 8.5-10.0″
255/35R2027″ (-2.2%)20″ x 8.5-10.0″
295/30R2027″ (-2.2%)20″ x 10.0-11.0″
255/30R2127″ (-2.2%)21″ x 8.5-9.5″
305/25R2127″ (-2.2%)21″ x 10.5-11.5″
205/55R1826.9″ (-2.6%)18″ x 5.5-7.5″
225/50R1826.9″ (-2.6%)18″ x 6.0-8.0″
285/35R1926.9″ (-2.6%)19″ x 9.5-11.0″
335/30R1926.9″ (-2.6%)19″ x 11.5-12.5″
145/60R2026.9″ (-2.6%)20″ x n/a
375/20R2126.9″ (-2.6%)21″ x n/a
155/80R1726.8″ (-3%)17″ x n/a
245/35R2026.8″ (-3%)20″ x 8.0-9.5″
345/25R2026.8″ (-3%)20″ x 12.0-13.0″
245/30R2126.8″ (-3%)21″ x 8.0-9.0″
295/25R2126.8″ (-3%)21″ x 10.0-11.0″

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: The tire size is for information purposes only, the measurement is an approximation, as tire manufacturers can have slight variations in their measurements. It's recommended to refer to the vehicle manufacturer's guidelines or consult with a tire mechanic to determine the correct tire size for your vehicle.


Share on:

Leave a Comment