Calculate tire rollout distance, circumference, or revolutions from two known values with inch or millimeter units by entering any two fields.
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Tire Rollout Formula
The following formulas are used to calculate tire rollout (tire circumference) and rollout distance.
C = \pi \cdot D R = C \cdot N
Variables:
- C is the tire circumference (also called tire rollout per revolution): the distance traveled in one complete tire revolution (in or mm).
- D is the tire diameter (in or mm).
- N is the number of tire revolutions (dimensionless).
- R is the rollout distance for N revolutions (in or mm).
To calculate tire rollout (circumference), multiply pi (π) by the tire diameter. To find the total rollout distance over multiple revolutions, multiply the tire circumference by the number of revolutions.
What is Tire Rollout?
Tire rollout is commonly used to mean the tire circumference: the distance traveled in one complete revolution of the tire. In practice, “rollout” can also refer to a measured distance per revolution under load (for example, using a chalk mark), which can differ slightly from π × diameter due to tire deflection, pressure, and wear. It is an important measurement for racers and car enthusiasts to optimize performance, as it affects the vehicle’s effective gearing, acceleration, and speed.
How to Calculate Tire Rollout?
The following steps outline how to calculate the Tire Rollout.
- First, measure the diameter of the tire (or use the manufacturer’s specified diameter) in inches or millimeters.
- Next, calculate the tire circumference (rollout per revolution) using C = π × D.
- If you want total distance over multiple tire rotations, determine the number of tire revolutions, N.
- Use the formula R = C × N to find the rollout distance.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Tire Diameter = 26 inches
Number of Revolutions = 10
