Scrub Radius Calculator

What is Scrub Radius and How to Calculate it?

Scrub radius is an important factor in vehicle design that affects how the vehicle handles and steers. It refers to the distance between the center of the tire’s contact patch and the point where the steering axis intersects the ground. A positive scrub radius means that the contact patch is outside the steering axis, while a negative scrub radius means it is inside the steering axis. The scrub radius can have a significant impact on the steering feel, tire wear, and overall performance of the vehicle.

Why is Scrub Radius Important?

Having the correct scrub radius is crucial for maintaining proper steering and handling characteristics of a vehicle. A positive scrub radius can provide better feedback to the driver and improve steering response. On the other hand, a negative scrub radius can lead to excessive tire wear and potentially dangerous handling characteristics.

Scrub Radius Calculator

How to Calculate Scrub Radius?

Calculating scrub radius involves measuring various factors of the vehicle’s suspension geometry. To calculate scrub radius, follow the steps below:

  1. Measure the distance between the center of the tire’s contact patch and the steering axis intersection point.
  2. Measure the distance between the centerline of the tire and the centerline of the wheel.
  3. Subtract the second measurement from the first to get the scrub radius.

It is important to note that scrub radius is not the sole factor that determines the handling characteristics of a vehicle. Other factors such as caster angle, camber angle, and toe angle also play a role in how a vehicle steers and handles.

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How to Use the Scrub Radius Calculator?

Our scrub radius calculator makes it easy to determine the scrub radius of your vehicle. Simply enter the required measurements into the calculator, and it will automatically calculate the scrub radius for you. This tool can be helpful for vehicle enthusiasts, mechanics, and engineers who want to optimize the handling and performance of a vehicle.

Factors Affecting Scrub Radius

Several factors can affect the scrub radius of a vehicle, including:

  • Wheel offset
  • Wheel width
  • Steering axis inclination
  • Suspension geometry

By understanding these factors and how they affect scrub radius, you can make informed decisions when modifying or designing a vehicle’s suspension system.


Scrub radius is a critical aspect of vehicle design that can have a significant impact on how a vehicle handles and steers. By calculating and optimizing the scrub radius of a vehicle, you can improve its performance and overall driving experience. Our scrub radius calculator simplifies the process of determining scrub radius, making it easier for enthusiasts and professionals to fine-tune their vehicle’s suspension geometry. Understanding the importance of scrub radius and how it influences vehicle dynamics is essential for anyone involved in vehicle design, modification, or maintenance.