How to Calculate Payload

The following is a guideline to help buyers correctly establish their utility requirements prior to initial purchase. This information is designed for end users to calculate payload and ultimately operate the vehicle within safe limits. Correct chassis selection will ensure the long life of the vehicle, sensible fuel economy, and good handling. To help you work out the Payload for your vehicle, terminology commonly as used on vehicle specification sheets is explained below, along with an example of the calculation.

Gross Vehicle Mass (GVM)

Gross Vehicle Mass (GVM) in kilograms, is displayed on the Vehicle Compliance Plate (usually found under the bonnet on the firewall) and is also shown on Vehicle Specification Sheets. The GVM is the maximum permissable weight of a fully loaded vehicle including the vehicle itself, driver and passengers, all accessories and options, and any type of truck body

Kerb Mass (KM)

Kerb Mass (KM) in kilograms is the mass (or weight) of the vehicle as a cab chassis, with no driver, passengers, payload or truck body, The Kerb Mass (KM) of utilities varies from model to model and data for popular vehicles is shown in the tables below.

Payload (P)

Payload (P) is the mass (or weight) of cargo/goods/tools the vehicle is permitted to carry.


Every person in a light truck is considered an occupant and is assumed to each weigh 75kgs. The total number of occupants for any truck is shown on the Vehicle Compliance Plate and possibly the Specification Sheet.

Vehicle Compliance Plate

An aluminium plate affixed to the firewall showing the GVM, the recommended number of occupants, the make and modelof the vehicle.


Tare is not the same as Kerb Mass and should not be used for these calculations.

Calculating Payload (P)

Payload (P) in kilograms is the GVM minus the following items….(KM) Kerb Mass, weight of the occupants, weight of fuel, oil and water, weight of any fitted options (towbar, bull bar, etc) and the weight of the truck body.

Payload (P) = GVM – (Kerb Mass + Fluids + Occupants + options + Truck Body)


The figures stated in this payload calculator are to be used only as a guide. Accessory masses vary between different body types and vehicle models. For more accurate mass values, please contact your vehicle and accessory manufacturer.