Understanding tow vehicle and caravan towing weights

When buying a new Snowy River Caravan, it is crucial to understand caravan towing weights and your tow vehicles’ towing capacity. There are some severe consequences for towing incorrectly, including:
  • Insurance companies will not cover you.
  • Towing overweight is against the law.
  • Incorrect loading can cause your caravan to sway and put lives in danger.
  • You can damage your tow vehicle’s motor, tow bar, and other running gear.
  • You could be fined and have your caravan towed away.
Spend the time to understand towing weights. At some point you’ll need to stop suddenly or swerve to avoid something and being incorrectly loaded could mean disaster. Getting your head around caravan towing weights should be the first thing you learn on your way to becoming a caravanner. So let’s get started…

Where to find the towing specifications for your tow vehicle

The tow vehicle manufacturer sets a towing capacity for every tow vehicle they make. This includes towing capacity, kerb weight (KW), tare weight, maximum tow ball mass (TBM), gross combination mass (GCM), gross vehicle mass (GVM), and using these, you can work out your maximum payload.
Try looking for a stamp inside one of your car’s doorframes for its tow ball weight and towing capacity. Otherwise, most of the information you need will be in your owner’s manual. When searching online for your vehicles towing capacity, make sure you include the exact make, model, and variant.
If you’ve lost your owners manual or are in any way unsure, try www.redbook.com.au or talk to the tow vehicle manufacturer or dealership.

Where to find your caravan towing weights

Every caravan manufacturer must fix a compliance plate to the caravans they build. This will include tare weight, empty tow ball weight, aggregate trailer mass (ATM), and gross trailer mass (GTM).
Generally, you’ll find the caravans complaince plate either inside the front boot or the tunnel boot.

What is the towing capacity of your tow vehicle?

The towing capacity is the maximum overall weight that your towing vehicle is legally allowed to tow. Your caravan’s aggregate trailer mass (ATM, explained later) should be less than your car’s towing capacity.All Snowy River Caravans are fitted with an electric brake controller

Braked towing capacity

If the caravan, pop-top or camper trailer you are towing has its own brakes, which most new ones will, this is the maximum overall weight you can legally tow, or maximum braked towing limit.
You must have a working brake controller installed on your towing vehicle and caravan. This rating in your owners manual is the maximum braked towing limit for the towing vechile.

Kerb weight (KW)

Kerb weight means how heavy your tow vehicle is, including oil, fluids, and a full tank of fuel, with nothing else (such as people, luggage etc.). Also, note that any accessories you or a dealer have fitted, like your tow bar, a bull bar, an extra spare wheel, or a roof rack, are not counted in your kerb weight.

The tare weight of your tow vehicle

Tare weight is how much your empty vehicle weighs, with 10 litres of fuel and all fluids filled. So it’s the same as kerb weight but with 10 litres of fuel instead of a full tank. Just like kerb weight, any aftermarket accessories added are not included.

Maximum tow ball weight/load capacity

The maximum tow ball weight, or tow ball download, is the maximum weight that can be transferred from the coupling of your caravan to the ball of your tow vehicle. When you hitch up, there will be a downward force from the coupling onto your tow vehicle, and it is only rated to take so much.

Gross combination mass (GCM)

The gross combination mass is the maximum weight of both the car and caravan combined as set by the vehicle manufacturer.

This includes all people, luggage, gear, fuel, water, accessories, etc. Your gross combined mass counts anything and everything loaded into your car and caravan.

Gross vehicle mass (GVM)

Gross vehicle mass means the maximum allowable weight your tow vehicle can be loaded up to set by vehicle manufacturers. This includes people, luggage, gear, fuel, tow ball mass from your caravan, everything.

Think of the gross vehicle mass as the most your tow vehicle can weigh, including the ball mass of the caravan you are towing.

What is your car's payload?

You can work out the payload, or how much weight you can load into your tow vehicle, by subtracting its kerb weight from its gross vehicle mass. The difference between these two equals your maximum payload with a full tank of fuel.

Your tow bar has a maximum tow capacity

The tow bar may be capable of towing more or less than your car can. If it is rated lower, you must not exceed those limits. If higher, you must not exceed your tow vehicle weights.

Caravan weights and what they mean

Tare mass, aggregate trailer mass, gross trailer mass, tow ball weight… You’re not the first and won’t be the last person to be confused by this. Becoming a caravanner means you have a legal and moral responsibility to tow responsibly. So read on and take note of how caravan weight is defined.

Tare weight of the caravan

The caravan tare weight is the empty weight, including all options and accessories fitted when the caravan was built. When the tare mass is measured, any gas bottles and water tanks are empty.

Tow ball mass (TBM)

Tow ball mass, which is often called ball weight or tow ball download, is the weight that the caravan’s coupling puts on the tow vehicle.

You can find an empty tow ball weight on the caravans compliance plate. Sometimes you will need to subtract the gross trailer mass (GTM) from the aggregate trailer mass (ATM) to work out your empty tow ball weight.

The tow ball load on your tow vehicle will change depending on how your caravan is loaded with luggage, whether your water tanks are full or empty, and how full or empty your gas bottles are. The easiest way to check this is with a tow ball weight scale.

Aggregate trailer mass (ATM)

The aggregate trailer mass of a caravan means the maximum allowable weight of your caravan when fully loaded and unhitched from a tow vehicle. This includes the weight of the caravan, any modifications made after it’s been built, water in the tanks, gas bottles, luggage, food, clothes, etc.

Caravan manufacturers set the ATM at the time of the build.

Gross trailer mass (GTM)

Gross trailer mass means the maximum total weight on the axles of the caravan when it is connected to a car. This is different from the aggregate trailer mass because when the caravan is hitched to a tow vehicle, the tow ball weight is being carried by the car and not on the caravan’s jockey wheel.

You can also work this out by taking the ATM of your caravan minus the tow ball weight.

What is your caravans payload?

To find your caravan’s payload, or how much you can load into it, simply minus the caravan tare weight from the ATM.

Remember that modifications after the build, caravan accessories, luggage, gas in the bottles, water in the tanks, any extra weight counted in the tare weight of the caravan comes out of your payload.


Now you know the essential weights to take note of and what they mean.

Once you understand these, you will know what you can and can’t safely and legally tow. Start by creating a list of your vehicle weights. Here are a few examples of what your list could look like;

Kerb weight: 2,330kg
Gross vehicle mass: 2,900kg
Maximum payload: 570kg
Maximum ball weight: 250kg
Maximum towing capacity: 2,500kg
Gross combination mass: 5,290kg

Towing a caravan at your maximum towing capacity of 2,500kg leaves you with 2,790kg of your gross combination mass (GCM).

If your caravans ball weight is at the maximum 250kg, that leaves 320kg of your GVM or maximum payload for everybody in your car and luggage etc.

Tow vehicles of this size would be best suited to towing our range of small caravans.

Here’s another example;

Kerb weight: 2,230kg
Gross vehicle mass: 2,990kg
Maximum payload: 760kg
Maximum ball weight: 300kg
Maximum towing capacity: 3,000kg
Gross combination mass: 5,990kg

Towing a caravan at your maximum towing capacity of 3,000kg leaves you with 2,990kg of your gross combination mass (GCM).

If your caravans ball weight is at the maximum 250kg, that leaves 320kg of your GVM or maximum payload for everybody in your car and luggage etc.

Tow vehicles of this size are suited to towing larger couples caravans without a slide-out, or our range of family caravans.

And one last example;

Kerb weight: 2,635kg
Gross vehicle mass: 3,350kg
Maximum payload: 715kg
Maximum ball weight: 350kg
Maximum towing capacity: 3,500kg
Gross combination mass: 6,730kg

Towing a caravan at your maximum towing capacity of 3,500kg leaves you with 3,230kg of your gross combination mass (GCM).

If your caravans ball weight is at the maximum 350kg that leaves 365kg of your GVM or maximum payload for everybody in your car and luggage etc.

Similar tow vehicles to this are capable of towing our range of slide-out caravans.

Upcoming 2024 Snowy River Caravans Models Register your interest today.