Enter the radius of the wheel and the width of the tire into the calculator to determine the wheel fitment. This calculator can also evaluate any of the variables given the others are known.

Wheel Fitment Formula

The following formula is used to calculate the wheel fitment.

WF = (2 * PI * (R + W/2)) / 63360


  • WF is the wheel fitment (inches) PI is the mathematical constant approximately equal to 3.14159 R is the radius of the wheel (inches) W is the width of the tire (inches)

To calculate the wheel fitment, multiply the radius of the wheel by 2 and then multiply the result by PI. Add the width of the tire divided by 2 to the result. Finally, divide the entire result by 63360 to convert the fitment from inches to miles.

What is a Wheel Fitment?

Wheel fitment refers to the process of ensuring that the wheels and tires on a vehicle are the correct size, type, and design for the vehicle’s make and model. This includes checking the bolt pattern, wheel diameter, width, offset, and backspacing. Proper wheel fitment is crucial for the vehicle’s performance, safety, and aesthetics. Incorrect fitment can lead to issues such as tire rubbing, poor handling, and potential damage to the vehicle.

How to Calculate Wheel Fitment?

The following steps outline how to calculate the Wheel Fitment using the given formula:

  1. First, determine the radius of the wheel (R) in inches.
  2. Next, determine the width of the tire (W) in inches.
  3. Next, calculate the sum of the radius and half of the width of the tire [(R + W/2)].
  4. Next, multiply the sum by 2 times the mathematical constant PI [(2 * PI * (R + W/2))].
  5. Finally, divide the result by 63360 to calculate the Wheel Fitment (WF).

Example Problem:

Use the following variables as an example problem to test your knowledge:

Radius of the wheel (R) = 15 inches

Width of the tire (W) = 8 inches