Weight Terminology - Quick Reference Guide

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Tare Caravan/Trailer Mass: This is the ‘dry’ weight of the caravan. It is the weight of the caravan as per the production build. It does not include water, gas, accessories and or added options post build. Any items such as additional batteries, solar panels, tool boxes, cargo etc that are added after manufacturing form part of the trailer/caravan payload.
Aggregate Caravan/Trailer Mass (ATM): ATM = Trailer/Caravan Tare weight plus the maximum allowable payload.
Example:
Caravan Tare weight: 2000kg
Caravan maximum payload: 400kg
ATM = 2400kg
To calculate your actual ATM, we need to place all caravan wheels and the jockey wheel on the scales and add the individual weights together.
Caravan/Trailer Payload: Payload is the caravan/trailer load carrying capacity. It is the difference between the ATM and Tare weight. This includes water, gas, accessories and cargo.
Gross Caravan/Trailer Mass (GTM): GTM = ATM minus the tow ball mass (TBM) Example:
ATM = 2400kg
TBM = 192kg
GTM = 2208kg

Tare: This is the ‘dry’ weight of the vehicle with only 10L of fuel, no cargo, passengers or accessories fitted.
Kerb: This is the same as Tare weight but with a full tank of fuel.
Gross Vehicle Mass (GVM): This is the Kerb weight plus passengers, cargo, accessories and tow ball mass (when trailer
connected).
Tow Ball Mass (TBM): This is the tow ball mass that is transferred from the trailer to the vehicle tow ball. All vehicles have a maximum allowable tow ball mass specified by the vehicle manufacturer (typically can be found on the vehicle tow placard).
Payload: Payload is any weight above and beyond the vehicle Kerb weight. Passengers, cargo, accessories (bull bars, tow bars, roof racks etc), vehicle modifications (larger tyres, after market wheels etc) and tow ball mass all attribute to vehicle payload.
Gross Combined Mass (GCM): This is the combined weight of the tow and towed vehicle (tow vehicle GVM + towed vehicle GTM). When calculating GCM, the tow ball mass of the trailer/caravan is included in the vehicle GVM.
Towing Capacity: This is the maximum allowable vehicle towing capacity as specified by the manufacturer. The maximum allowable towing capacity is impacted directly by the vehicle GVM at the time of towing.