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Calcimator

Race Weight Penalty Calculator

Calculate the lap time penalty from additional weight on a race car. Understand how ballast, fuel load, or driver weight affects performance across different track types.

Inputs

lb
lb
sec

Results

Time Penalty per Lap

0.71 sec

Percent Slower0.75%
Total Penalty (10 Laps)7.13 sec
Equivalent HP Loss6.2 HP
How to Use This Calculator
  1. Enter Base Vehicle Weight, Additional Weight, and Base Lap Time.
  2. Set Track Type.
  3. Review the Time Penalty per Lap (sec) result.
  4. Use Percent Slower (%) and Total Penalty (10 Laps) (sec) to inform your decision.

How the result changes with Additional Weight

Additional WeightTime Penalty per Lap
501.43 sec
1754.99 sec
3259.26 sec
45012.83 sec

What each input means

Base Vehicle Weight
Minimum race weight of the car without additional ballast in kg. Use scrutineering weight.
Additional Weight
Extra weight being added in kg (ballast, heavier driver, extra fuel, equipment).
Base Lap Time
Lap time at base weight. Use your best consistent lap from practice or qualifying.
Track Type
0 = Short/technical (most weight-sensitive), 1 = Medium circuit, 2 = Long/fast (least weight-sensitive).

What each result means

Time Penalty per Lap
Estimated time lost per lap due to additional weight.
Percent Slower
Percentage increase in lap time from the added weight.
Total Penalty (10 Laps)
Cumulative time lost over a 10-lap stint.
Equivalent HP Loss
How much extra horsepower you would need to offset the weight penalty (assumes ~300 HP base).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Base Vehicle Weight = 1200, Additional Weight = 25, Base Lap Time = 95, Track Type = 1 = 4 input(s) provided
  2. Calculate Time Penalty per Lap
    Time Penalty per Lap
    0.713 = 0.713
  3. Calculate Percent Slower
    Percent Slower
    0.75 = 0.75
  4. Calculate Total Penalty
    Total Penalty
    7.125 = 7.125

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