Vehicle & Trailer Weight Definitions & Acronyms

The GVM is the maximum allowable total mass of a fully loaded motor vehicle as specified by the manufacturer. Consisting of the tare mass (base weight of the vehicle) plus the load. The load includes fuel, all occupants, cargo, tow bar and any add-on accessories. Typically, you can find the GVM alongside the VIN number on the compliance plate on the vehicle.

The payload, sometimes called laden weight, is the weight of the load being carried on the trailer. This includes equipment, tools, spare tyres, extra fuel and load restraints etc. To calculate the payload of a trailer take the ATM (Aggregate Trailer Mass) and minus the TARE Weight. (ATM – TARE = Payload)

The TARE weight, sometimes called unladen weight, is the base weight of the empty trailer whilst unhitched from the tow vehicle, no payload (such as equipment) or load restraints.

Typically, you can find the TARE weight alongside the VIN number on the compliance plate fitted to the trailer. The compliance plate is usually located on the draw bar or rear of the trailer.

The GVM is the maximum allowable total mass of a fully loaded motor vehicle as specified by the manufacturer. Whereas the TARE weight is the base weight of the empty vehicle or trailer. Trailers must be unhitched from any tow vehicle, no payload or load restraints.

The ATM (Aggregate Trailer Mass) is the weight of the trailer fully loaded when it is unhitched from the tow vehicle whilst sitting on its jockey wheel or stand. As a rule, you must not exceed the rated ATM of the trailer as specified on the compliance plate on the trailer.

The GTM (Gross Trailer Mass) is the total weight of a trailer, fully loaded when it is hitched to the tow vehicle. As a rule, you must not exceed the rated GTM of the trailer as specified on the compliance plate.

Aggregate Trailer Mass refers to the fully loaded trailer but unhitched from the vehicle, whereas Gross Trailer Mass refers to a fully loaded trailer hitched to a vehicle. GTM takes into account the load being carried on the tow ball. Typically, you can find the (GTM or ATM) alongside the VIN number on the compliance plate on the trailer.

The Tow Ball Mass is the load exerted on the tow ball of the tow vehicle. Generally, the ball weight is around 10% of the ATM.

The GCM (Gross Combined Mass) refers to the weight of the tow vehicle and trailer hitched together while both are fully loaded (including passengers, equipment, fuel and tools). As a rule, you must not exceed the rated GCM of the tow vehicle as specified by the manufacturer. Typically, you can find the GCM alongside the VIN number on the compliance plate on the vehicle.

Gross Vehicle Mass (GVM) refers to the maximum allowable total mass of a fully loaded motor vehicle as specified by the manufacturer. Whereas Gross Combined Mass (GCM) refers to the weight of the tow vehicle and trailer hitched together while both are fully loaded (including passengers, equipment, fuel and tools). Typically, you can find the GVM and GCM alongside the VIN number on the compliance plate on the vehicle.