Understanding GVM, GCM, TARE, TBM, GTM & ATM: What Do These Terms Mean for Your Vehicle?
If you've ever looked into towing a caravan, hauling a trailer, or just making sure your vehicle stays within legal weight limits, you’ve probably come across a bunch of confusing acronyms - GVM, GCM, TARE, TBM, GTM, and ATM. It might feel like a secret code, but don’t worry! At EvaluWeight, we’re here to break it down in plain English so you can hit the road with confidence.
THE TOW VEHICLE
Tare Weight (TARE)
The TARE weight is the total weight (includes fluids like coolants and approx. 10ltrs of fuel) of the vehicle when it leaves the factory. It excludes any payload. Payload is any mass you add after delivery. This includes passengers, luggage, and aftermarket accessories such as bull bars and canopies.
Braked Towing Capacity (BTC)
Braked Towing Capacity is the maximum allowable weight that can be towed by the vehicle.
Gross Vehicle Mass (GVM)
Gross Vehicle Mass is a total weight rating set by the manufacturers of the fully loaded vehicle. This includes all additional mass including full fuel tanks, passengers, luggage and equipment. GVM = TARE + Maximum Payload
Gross Vehicle Mass In Combination (GVM)
Gross Vehicle Mass in Combination is the total weight of the vehicle plus the weight exerted on the tow ball by the caravan when coupled. When towing, the tow ball mass is included in the tow vehicle’s payload.
Gross Combination Mass (GCM)
Gross Combination Mass is the total weight of the fully loaded tow vehicle and caravan. GCM = GVM + GTM
THE CARAVAN
Tare Mass (TARE)
The TARE Mass is the dry unladen weight of the caravan. It excludes any fluids such as water and gas.
Tow Ball Mass (TBM)
Sometimes referred to as Tow Ball Weight, is the weight the caravan imposes on the vehicle at the hitch.
Gross Trailer Mass (GTM)
This is the maximum weight of the loaded caravan that can be supported by its wheels and axles. It does not include the weight supported by the towing vehicle or jockey wheel when parked.
Aggregate Trailer Mass (ATM)
The Aggregate Trailer Mass is the maximum weight of the caravan including payload and the weight of the tow ball mass. ATM = GTM + TBM
Why Should You Care About These Numbers?
Ignoring weight limits isn’t just about avoiding fines - it’s about safety. Overloading can make your vehicle harder to control, consume fuel faster, and cause mechanical failures that can lead to serious accidents. At EvaluWeight, we help you make sure your setup is road-ready, legal, and safe.
Not sure if your vehicle or trailer is within limits? Book a weighing session with EvaluWeight today and tow with confidence!