Tire Size 305/50r20 in Inches


Tire size 305/50r20 is a popular size for various types of vehicles, offering a balance of performance and aesthetics. We will explore the dimensions of this tire size in inches and discuss the relevant specifications.

/ R
Tire Height
Section Width
Sidewall Height
Rim Size
Tire 1 Front View
Tire 1 Side View
Tire 1 Wheel
circumference 1


305/50r20 in Inches

For a thorough understanding of tire features and metrics, refer to the following table, which provides comprehensive information on their breakdown.

Tire Height814 mm32″
Tread Width305 mm12″
Rim Diameter508 mm20″
Sidewall Height153 mm6″
Circumference2556 mm100.5″
Revolutions391 per km630 per mile

Tire Size 305/50r20 Breakdown
Let’s break down the tire size 305/50r20 to better understand its components:

  • 305: The first number, 305, represents the tire’s width in millimeters. In this case, the tire has a width of 305 millimeters.
  • 50: The second number, 50, is the aspect ratio or the tire’s profile. It indicates the sidewall height as a percentage of the tire’s width. The sidewall height is 50% of the tire’s width in this case.
  • R: The “R” stands for radial construction. Radial tires are the most common type of tire construction, featuring internal layers of fabric or steel belts that run radially across the tire.
  • 20: The last number, 20, represents the rim diameter in inches. It indicates the size of the wheel on which the tire is mounted.

So, the tire size 305/50r20 denotes a tire with a width of 305 millimeters, a sidewall height of 50% of the width, radial construction, and compatibility with a 20-inch rim diameter.

Tire Size 30550r20 in Inches

Replacement Tire Size
It is advisable to select ones with an overall diameter that closely matches the 305/50r20 tire size, preferably within a 3% range.

Tire SizeOverall DiameterDifference
245/60R2031.6″ (802 mm)-1.5%
295/50R2031.7″ (804 mm)-1.2%
275/55R2031.9″ (810 mm)-0.5%
255/60R2032″ (814 mm)0%
285/55R2032.4″ (822 mm)1%
315/50R2032.4″ (824 mm)1.2%
265/60R2032.5″ (826 mm)1.5%
295/55R2032.8″ (832 mm)2.2%
325/50R2032.8″ (834 mm)2.5%
275/60R2033″ (838 mm)2.9%

Tire Height: The tire size 305/50r20 has an overall diameter of 814 mm or approximately 32 inches. This measurement refers to the height of the tire from the ground to the top of the tread.

This diameter is essential for ensuring proper clearance within the wheel well and can significantly impact a vehicle’s handling, acceleration, and fuel efficiency.

Tread Width: With a tread width of 305 mm or 12 inches, the 305/50r20 tire size provides a wide contact patch with the road. The increased contact patch improves traction, stability, and overall performance, particularly in wet or slippery conditions.

Rim Diameter: The 305/50r20 tire size is designed to fit on a 20-inch (508 mm) diameter rim. This rim diameter is common among modern vehicles and provides a stylish appearance while maintaining a balance of performance and ride comfort.

Sidewall Height: The sidewall height of the 305/50r20 tire size is 153 mm or approximately 6 inches. This measurement, also known as the tire’s aspect ratio, is crucial for determining ride comfort and handling characteristics. 

A taller sidewall height generally provides a more comfortable ride and absorbs more road imperfections. However, it can also reduce handling capabilities compared to a tire with a lower sidewall height.

Circumference: The 305/50r20 tire size has a circumference of 2556 mm or approximately 100.5 inches. This measurement is essential for calculating the tire’s revolutions per mile, which can impact a vehicle’s speedometer readings and odometer accuracy.

Revolutions: The 305/50r20 tire size has revolutions per mile value of 630 or 391 revolutions per kilometer. This value is important for vehicle owners to know because it can affect the accuracy of the vehicle’s speedometer and odometer readings.

A tire with higher revolutions per mile value will cause the speedometer to read faster, while a tire with a lower value will cause the speedometer to read slower.

Tire Construction: The “R” in the tire size 305/50r20 stands for “Radial,” which refers to the tire’s construction method. Radial tires are the most common type of tire construction, offering improved ride comfort, longer tread life, and better fuel efficiency compared to older bias-ply tires. Radial tires feature steel belts that run perpendicular to the tread’s centerline, adding strength and durability.

Our Observations
The tire size 305/50r20, equivalent to 32x12R20 in inches, provides a balanced combination of performance and aesthetics for a variety of vehicles.

The 32-inch overall diameter and 12-inch tread width offer ample clearance within the wheel well and a wide contact patch with the road, enhancing traction and stability. 

The 20-inch rim diameter lends a stylish appearance while maintaining ride comfort and performance. The 6-inch sidewall height offers a comfortable ride, and the radial tire construction ensures durability and improved fuel efficiency.

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