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Payload Capacity

Free Payload Capacity calculator with clear step-by-step results.

About Payload Capacity

Payload is gross vehicle mass minus kerb mass, but that headline figure has to fund occupants, fitted accessories and - critically - the downward load a trailer puts on the towball, which counts against the tow vehicle rather than the trailer. What remains is the real cargo allowance.

Formulas

Gross payload

Payload = gross vehicle mass rating - kerb mass

Available cargo

Available = gross payload - occupants - accessories - towball download

Worked example

With the default values below, Payload Capacity returns Payload left for cargo of 930.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Gross vehicle mass ratingminimum 100 kg
3,500 kg
Kerb massminimum 100 kg
2,150 kg
Occupantsaccepts 0–9
2
Mass allowed per occupantminimum 30 kg
75 kg
Fitted accessoriesminimum 0 kg
120 kg
Towball download from a trailerminimum 0 kg
150 kg

Results

Payload left for cargo
930.0 kg
Total payload capacity
1,350.0 kg
Mass taken by occupants
150.0 kg
Payload already committed
31.1% %

Step by step

  1. 1Values used
  2. 2Gross payload
  3. 3Available cargo
  4. 4Payload left for cargo= 930.0 kg
  5. 5Total payload capacity= 1,350.0 kg
  6. 6Mass taken by occupants= 150.0 kg
  7. 7Payload already committed= 31.1 %

Assumptions and limits

  • The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax or compounding frequency into account.
  • Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Exceeding gross vehicle mass, axle limits or towing ratings is illegal and dangerous, and can invalidate insurance. Verify against the manufacturer's plate and have the loaded vehicle weighed.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Exceeding gross vehicle mass, axle limits or towing ratings is illegal and dangerous, and can invalidate insurance. Verify against the manufacturer's plate and have the loaded vehicle weighed.

Frequently Asked Questions

Does towball load really count against payload?

Yes. The vertical load the coupling applies is carried by the vehicle's suspension and counts toward gross vehicle mass, which is how many loaded tow vehicles end up illegally overweight.

Is kerb mass the figure in the brochure?

Often optimistically so. Brochure kerb mass may exclude a full fuel tank, spare wheel or optional equipment. Weighing the vehicle is the only reliable method.

Related Calculators

Payload Capacity – Calculate Payload left for cargo