Caravan Weights Explained: What’s TARE, GVM, ATM, GTM, GCM?

By: AOT Staff Writer

Caravan weights can be confusing for newcomers, but they’re crucial to understand for safe and legal towing. Let’s break down these terms and explain how you can make sense of it all:


TARE Weight (TARE)

TARE weight is the weight of your caravan when it is completely empty. This includes the weight of the caravan’s body, chassis, and any standard features it comes with. It doesn’t include any additional items or personal belongings you may add later.

GVM Gross Vehicle Mass

Gross Vehicle Mass (GVM)

GVM refers to the maximum permissible weight of your caravan when it’s fully loaded with all your belongings, water, gas, and everything else you plan to carry. Exceeding the GVM can be dangerous and illegal.

ATM Aggregate Trailer Mass

Aggregate Trailer Mass (ATM)

ATM is the total weight of your caravan when it’s loaded with everything you intend to take on your trip, including water, gas, and all your belongings. This weight must not exceed the caravan’s rated ATM, as it ensures the caravan is safe to tow.

GTM Gross Trailer Mass

Gross Trailer Mass (GTM)

GTM is similar to ATM, but it represents the weight of the loaded caravan, excluding the weight carried by the tow vehicle’s coupling point (the point where the caravan attaches to the tow vehicle). GTM is vital to ensure proper weight distribution and safe towing.

GCM Gross Combined Mass

Gross Combined Mass (GCM)

GCM is the total permissible weight of both your tow vehicle and your caravan combined. It considers the weight of the tow vehicle, passengers, cargo, and the caravan. Exceeding the GCM can result in unsafe towing conditions.

Tow Ball Weight

Tow Ball Weight

Tow Ball Weight, also known as Hitch Weight or Tongue Weight, is the downward force exerted on the tow ball or hitch by the weight of the trailer or caravan. It’s a crucial factor in safe and stable towing. This weight is typically expressed in kilograms or pounds.

A proper tow ball weight ensures that the trailer or caravan is balanced and stable while being towed. If the TBW is too light, the trailer may sway or fishtail, making it challenging to control. On the other hand, if it’s too heavy, it can overload the rear suspension of the tow vehicle and cause handling issues.

The ideal TBW usually falls within a recommended range specified by the vehicle manufacturer or the trailer manufacturer. It’s essential to adhere to these recommendations for safe towing.


  • Payload refers to the total weight that a vehicle can carry, including passengers, cargo, and any additional items. It’s typically expressed in kilograms or pounds and represents the difference between the vehicle’s Gross Vehicle Mass (GVM) and its Tare Weight (empty weight).
  • Payload includes not only the weight of passengers and their belongings but also any aftermarket accessories or modifications you’ve added to the vehicle, such as roof racks, bull bars, or cargo. It’s essential to stay within the vehicle’s specified payload limit to ensure safe operation.
  • When calculating payload, it’s crucial to consider the weight distribution within the vehicle to maintain proper handling and stability. Overloading a vehicle beyond its payload capacity can affect braking performance, steering control, and overall safety.

Here’s a practical example to help illustrate these concepts:

Imagine you have an SUV with a GVM of 3,000 kg and a Tare Weight of 2,000 kg. This means your vehicle has a maximum payload capacity of 1,000 kg (3,000 kg – 2,000 kg). If you load the vehicle with 800 kg of passengers, luggage, and accessories, you have 200 kg of remaining payload capacity for any additional items or a trailer’s tow ball weight.

Here’s a simple analogy to help you remember these terms

Think of your caravan as a backpack. The TARE weight is the empty backpack’s weight. The GVM is like the maximum weight you can safely load into the backpack without causing damage or making it uncomfortable to carry. The ATM is the weight of the fully loaded backpack, including everything you intend to take on your journey. The GTM is the weight of the loaded backpack minus what’s carried by the straps that attach to your body (the tow vehicle). Finally, the GCM is the total combined weight of your body (the tow vehicle) and the backpack (the caravan).

It’s crucial to know and adhere to these weight ratings to ensure safe and legal towing, avoid accidents, and prolong the life of your caravan and tow vehicle. Always refer to the manufacturer’s specifications and consult experts or authorities if you’re unsure about any of these weights.

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