235/40R18 in inches

Tire size specifications, like 235/40R18, provide vital information about a tire’s dimensions and capabilities. The tire size 235/40R18 is equivalent to 25.4×9.3R18 in inches.

/ R
FeatureMetricInches
Tire Height
Section Width
Circumference
Sidewall Height
Revolutions
Rim Size
Tire 1 Front View
Width
Dia.
Tire 1 Side View
Tire 1 Wheel
circumference 1
Circ.
Rim
Wall
Revs/Mile

 

Overall Diameter

The 235/40R18 tire size is characterized by an overall diameter of 25.4 inches, measured from one edge to the other. This measurement reflects the tire’s complete height when filled to the recommended pressure.

Tread Width

The 235/40R18 tire has a tread or section width of 9.3 inches. This dimension represents the distance between one sidewall to the other, signifying the contact area with the road surface.

Tire Circumference

The 235/40R18 tire has a circumference of 79.8 inches, representing the linear distance traveled in a single revolution. This measurement is crucial for determining speed, distance, and revolutions per minute (RPM).

Sidewall Height

The 235/40R18 tires feature a sidewall height of 3.7 inches. This measurement represents the vertical distance from the outer edge of the rim to the outer edge of the tire’s tread.

It plays a crucial role in defining the tire’s profile, impacting both ride comfort and handling attributes.

Revolutions Per Mile

The 235/40R18 tire size completes around 794 revolutions per mile. This metric signifies the full rotations the tire makes while covering one mile.

It’s important to grasp this value, as it plays a significant role in odometer readings, speed calculations, and aspects of fuel efficiency.

Wheel Size

The appropriate rim size for 235/40R18 tires is 18 inches in diameter. This detail becomes crucial when contemplating wheel replacement or upgrade, as it guarantees proper fitting of the tire onto the rim.

Construction Type


Finally, the 235/40R18 tires utilize a radial construction. In radial tire design, the internal layers or “plies” are oriented perpendicular to the direction of travel.

This configuration enhances heat dissipation and elevates overall performance, surpassing alternative construction methods.

What Does 235/40R18 Mean?

The term “235/40R18” refers to the size and specifications of a tire. Here’s a breakdown of what each part of the designation means:

  • 235: This number represents the width of the tire in millimeters. In this case, the tire is 235 millimeters wide from sidewall to sidewall.
  • 40: This number indicates the aspect ratio, which is the ratio of the tire’s sidewall height to its width. In this example, the aspect ratio is 40, meaning the sidewall height is 40% of the tire’s width.
  • R: This letter stands for “radial,” which is the most common type of tire construction. Radial tires have ply cords that run perpendicular to the direction of travel.
  • 18: This number represents the diameter of the wheel, in inches, on which the tire is designed to fit.

So, in summary, a tire with the designation 235/40R18 is a radial tire that is 235 millimeters wide, with a sidewall height that is 40% of the width, and it is designed to fit a 18-inch wheel.

235 40r18 in inches

What Is 235/40R18 In Inches?

The tire size 235/40R18 can be expressed in inches as approximately 9.3 inches wide, 3.7 inches tall in sidewall, and designed to fit a 18-inch wheel rim. The 235/40R18 also has a circumference of 79.8 inches and It completes 794 revolutions per mile.

235/40R18 Equivalent

The tire size 235/40R18 is equivalent with a size of 25.4x9.3R18 in inches. This correlation is pivotal for precision in tire selection and optimal vehicle performance.

How Tall Is A 235/40R18 Tire?

The height of a 235/40R18 tire, expressed through its diameter, is approximately 25.4 inches (645.2 mm). In short, A 235/40R18 tire size is 25.4 inches (645.2 mm) tall.

The height of the tire is subject to slight variations, determined by both the brand and model of the tire, in addition to the amount of air pressure it holds.

How Wide Is A 235/40R18 Tire?

The width of a 235/40R18 tire is 9.3 inches (235 millimeters). The first number in the tire size (235) represents the tire’s nominal width in millimeters from sidewall to sidewall when mounted on a specified width wheel. Therefore, the 235/40R18 tire size is 9.3 inches (235 mm) wide.

235 40r18 in inches

What Size Rim For 235/40R18?

The size of the rim for a 235/40R18 tire is 18 inches in wheel diameter. In the tire size 235/40R18, the number “18” at the end indicates the diameter of the wheel (rim) in inches that the tire is designed to fit.

Tire SizeOverall DiameterDifference
125/70R1824.9″-1.90%
255/35R1825″-1.60%
295/30R1825″-1.60%
225/40R1825.1″-1.20%
305/30R1825.2″-0.60%
205/45R1825.2″-0.60%
265/35R1825.3″-0.30%
155/60R1825.3″-0.30%
145/65R1825.4″0.00%
315/30R1825.5″0.30%
135/70R1825.5″0.30%
275/35R1825.6″0.60%
215/45R1825.6″0.90%
245/40R1825.7″1.20%
285/35R1825.9″1.90%
225/45R1825.9″2.20%
335/30R1825.9″2.00%
185/55R1826″2.50%

Our Observation
Upon analyzing the dimensions and specifications of the 235/40r18 tire size, several key points come to light. The tire’s overall diameter of 645 mm (25.4 inches) and tread width of 235 mm (9.3 inches) indicate a balanced combination of performance and stability. The 18-inch rim diameter is popular among sporty and high-performance vehicles, further emphasizing the tire’s capabilities.

With a sidewall height of 94 mm (3.7 inches), the tire strikes a balance between ride comfort and responsive handling. The circumference of 2025.3 mm (79.8 inches) provides insights into the tire’s rolling characteristics and can impact speedometer accuracy, an important consideration for drivers who rely on accurate speed readings.

The 235/40r18 tire’s revolutions per mile value of approximately 794 indicates how frequently the tire rotates over a given distance. This information is useful for various calculations, such as determining fuel consumption and estimating tire wear.

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