Corner weight calculator

Vehicle Configuration

Input Corner Weights

Weight Distribution Results

Target Mode

Target Mode allows you to work backwards from desired weight distribution percentages to determine the ideal corner weights. First check the recommended ranges below for your vehicle type, then enter your target percentages to see what adjustments are needed.

* For accurate results, measure on a level surface with all fluids at proper levels and equal tire pressures. Driver weight should be accounted for in performance applications.

Understanding Corner Weights

Corner Weight Measurement

The individual weight measured at each wheel of a vehicle. These measurements are taken using specialized scales or weight pads placed under each tire, with the vehicle in its normal driving position.

Total Vehicle Weight

The sum of all four corner weights. This represents the complete weight of the vehicle including all fluids, fuel, and any accessories or modifications.

When measuring corner weights for performance applications, it's recommended to include driver weight (and passenger weight if regularly carried) to get an accurate picture of actual racing or driving conditions.

Front-to-Rear Distribution

• Front Weight Percentage: The percentage of total vehicle weight supported by the front axle. Calculated as (Front Left + Front Right) ÷ Total Weight × 100%.
• Rear Weight Percentage: The percentage of total vehicle weight supported by the rear axle. Calculated as (Rear Left + Rear Right) ÷ Total Weight × 100%.

Front-to-rear weight distribution significantly affects a vehicle's handling characteristics, particularly during acceleration and braking:

• Front-heavy (55-60% front): Common in front-wheel drive vehicles. Tends to promote understeer, especially when accelerating out of corners.
• Balanced (50/50): Ideal for balanced handling. Common target for sports cars.
• Rear-heavy (55-60% rear): Common in rear-engine vehicles. Can promote oversteer but provides better traction for rear-wheel drive vehicles.

Left-to-Right Distribution

The side-to-side weight balance of a vehicle. For road cars, this should ideally be close to 50/50 for balanced handling.

• Left Weight Percentage: The percentage of weight on the left side of the vehicle. Calculated as (Front Left + Rear Left) ÷ Total Weight × 100%.
• Right Weight Percentage: The percentage of weight on the right side of the vehicle. Calculated as (Front Right + Rear Right) ÷ Total Weight × 100%.

For road racing, a balanced left-right distribution is desirable. For oval track racing (where turns are predominantly in one direction), an intentional left or right bias may be implemented.

Cross Weight (Wedge)

The diagonal weight distribution from front-left to rear-right, expressed as a percentage of total vehicle weight. This is one of the most critical measurements for vehicle handling balance.

Calculated as: (Front Left + Rear Right) ÷ Total Weight × 100%

• 50% Cross Weight: Neutral handling balance where the vehicle has equal grip in left and right turns.
• Greater than 50% (Positive Wedge): Promotes oversteer, where the rear of the vehicle tends to step out during cornering.
• Less than 50% (Negative Wedge): Promotes understeer, where the vehicle tends to push toward the outside of the turn.

Typical Target Values

Optimal weight distribution varies by application, but some general guidelines include:

• Street Cars: 50-52% cross weight, balanced left-right distribution, and front-rear distribution as designed by the manufacturer.
• Front-Wheel Drive Race Cars: 52-54% cross weight, slightly front-biased weight distribution (55-58% front).
• Rear-Wheel Drive Race Cars: 49-52% cross weight, rear-biased weight distribution for better traction (48-50% front).
• Circuit Racing: Near 50% cross weight for balanced left and right turn performance.
• Oval Track Racing: Typically 52-58% cross weight to help the car turn left more effectively.

Adjusting Corner Weights

Corner weights can be altered through several methods:

• Spring Height Adjustments: Raising or lowering the spring perch height on adjustable coilovers or torsion bars.
• Spring Rate Changes: Installing springs with different rates can affect weight transfer characteristics.
• Weight Placement: Strategically positioning components, ballast, or accessories within the vehicle.
• Anti-Roll Bar Adjustments: Changing sway bar stiffness to affect weight transfer during cornering.
• Chassis Adjustments: Some race cars allow for chassis adjustments like wedge bolts or panhard bar height.

Best Practices for Measurement

To ensure accurate corner weight measurements:

• Use a level surface for measurement
• Ensure equal tire pressures at all four corners
• Fill all fluids to normal operating levels
• Include driver weight (and passenger weight if applicable)
• Set the suspension at normal ride height
• Make sure the steering is centered
• Eliminate any wind effects or temperature gradients
• Allow suspension to settle after each adjustment

Note that corner weighting has some important considerations:

• Changes in fuel level can significantly affect weight distribution
• Different driver weights will change the balance
• Temperature changes can affect suspension component behaviors
• Tire wear and pressure changes impact weight distribution over time
• Aerodynamic downforce at speed will change effective corner weights
• Corner weighting should be performed after any significant suspension or chassis modifications
• Track-specific setups may require different weight distributions based on the nature of the corners and surface