Center of Gravity Height Calculator
Determine the vertical CoG for vehicles using the axle-lift method.
What is Center of Gravity (CoG) Height?
The Center of Gravity (CoG) height represents the vertical point in a vehicle where the entire weight of the vehicle is concentrated. In automotive engineering and racing, CoG height is a critical metric that influences weight transfer during acceleration, braking, and cornering. A lower CoG generally leads to better stability, reduced body roll, and a lower risk of rollover incidents.
How to Calculate CoG Height
Calculating the vertical position of the CoG requires weighing the vehicle on level ground and then weighing it again with one end (usually the rear) elevated. By measuring the change in weight distribution as the vehicle tilts, we can use trigonometry to solve for the vertical height. This calculator uses the standard automotive formula:
Formula: CoG Height = Axle Radius + [ (Change in Weight * Wheelbase * Horizontal Distance) / (Total Weight * Rise Height) ]
Why CoG Height Matters
Whether you are building a custom rock crawler, a track-focused sports car, or analyzing a fleet vehicle, knowing the CoG height allows you to optimize suspension geometry. If the CoG is too high, the vehicle will experience excessive load transfer, which can overload tires and decrease overall grip. By quantifying this value, engineers can make informed decisions about battery placement in EVs or engine mounting heights in performance builds.
Frequently Asked Questions
Q: What units should I use?
A: You can use any consistent units (inches and pounds or millimeters and kilograms). The result will be in the same unit of length you provided.
Q: How high should I lift the vehicle?
A: For accurate results, a lift of at least 10-15 inches is recommended to ensure a measurable change in weight distribution.
Q: Does fuel level affect CoG?
A: Yes, fuel is a significant weight. For the most accurate "real-world" measurement, the vehicle should be weighed with the driver and typical fuel load.