Motorhome Weights Explained

Motorhome Weights Explained (Calculator + How to Weigh)

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Motorhomes are a great way to get out and explore Australia. With an onboard kitchen, ensuite, beds, dining table and plenty of storage capacity, they’re the perfect all-in-one travel home.

Whether you buy or hire a motorhome, it’s important to understand motorhome weights so that you know which licence you’ll need, as well as keeping within the legal weight limits.

Tare weight, GVM (Gross Vehicle Mass) and payload are the three important motorhome weight terms you will need to become familiar with.

Here’s everything you need to know about motorhome weights in Australia, plus how to weigh your own motorhome.

Feel free to make full use of the Motorhome Weights Calculator, which will work out your available payload.

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Motorhome Weights Explained

Tare Weight

Motorhome Tare Weight

Tare weight is the weight of an empty motorhome with all of its running fluids (such as oil, coolant, brake fluid etc.), but with only 10 litres of fuel in the tank.

Essentially, tare weight is what the motorhome weighs as it drives out of the factory (with all of its fluids and only 10 litres of fuel). Tare does not include additional accessories, modifications, the driver, passengers or luggage.

The motorhome tare weight should be stamped onto the vehicle compliance plate.

TARE WEIGHT = Weight of Empty Motorhome + Oil & Fluids + 10L Fuel

Gross Vehicle Mass (GVM)

Motorhome GVM Weight

Gross Vehicle Mass (GVM) is the maximum allowable weight of the motorhome, including passengers, luggage and accessories.

The GVM is set by the motorhome manufacturer, which states the maximum weight that the motorhome can be at any given time and must not be exceeded.

The GVM of the motorhome should be stamped onto the compliance plate.

GVM = Maximum Allowable Weight of Motorhome

Payload

Motorhome Payload

Payload or ‘loading weight’ is the combined weight of all items that you can add or load into your motorhome. This is anything above the tare weight without exceeding the GVM.

Consider payload as your available carrying capacity (i.e. how much “stuff” you can load into the motorhome).

Working out your payload is simple. Just take the motorhome’s maximum weight (GVM) and minus the motorhome’s empty weight (tare).

What you’re left with is the amount of weight allowance you have for your luggage, water, fuel, passengers, accessories and gear.

Motorhome Payload Allowance Includes:

  • Driver
  • Passengers
  • Full fuel tank
  • Full water tanks
  • Full waste water tanks
  • Accessories (e.g. bull bar, rear bar, jerry can holders)
  • Modifications (e.g. extra batteries & solar panels)
  • Luggage
  • Food
  • Camping gear etc.
PAYLOAD = GVM – Tare Weight
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Extra Motorhome Weights if Towing a Car or Trailer

If you decide to tow a car or trailer behind your motorhome, there are a few additional weight terms that you’ll need to know and understand.

Towing Capacity

Motorhome Towing Capacity

Towing capacity is the maximum weight that your motorhome can legally tow. This figure is set by the motorhome’s manufacturer and cannot be changed.

It’s important to check your motorhome’s towing capacity to ensure it will be high enough to tow whatever vehicle or trailer you wish behind it.

In addition, if the trailer or car that you’re towing weighs more than 750 kg, it must have its own independent braking system.

TOWING CAPACITY = Maximum Allowable Weight the Motorhome Can Tow

Towbar Ratings

Before hitching anything up to the motorhome, it’s important to check the towbar ratings to ensure they’re high enough to tow the intended weight of the additional vehicle or trailer.

There are two towbar ratings to check, which should be stamped onto the towbar compliance plate itself.

Towbar Ratings:

  • Max Ball Load – Maximum amount of tow ball weight that can be applied to the towbar
  • Max Trailer Weight – Heaviest car/ trailer weight that the towbar is rated to tow
TOWBAR RATING = Maximum Weight Towbar is Rated to Accept

Tow Ball Weight

Motorhome Tow Ball Weight

The next thing to consider is the amount of weight that the tow ball is transferring onto the rear of the motorhome. This is called Tow Ball Weight (TBW).

Since the motorhome is a much heavier vehicle than the car or trailer that you’re towing, you won’t have the same tow ball weight issues that can come with towing a caravan.

However, tow ball weight is included in your payload allowance, which means you’ll have less weight available for luggage, food, water and gear.

Here’s a more in-depth look at how tow ball weight works.

TBW = Trailer Weight Transferred onto Motorhome Towbar

Gross Combination Mass (GCM)

Motorhome GCM (Gross Combination Mass)

The Gross Combination Mass (GCM) is the maximum allowable weight of your motorhome, plus the towed trailer (or car) combined. GCM is set by the manufacturer of your motorhome and can’t be changed.

This is the combined weight of the fully loaded motorhome, plus the fully loaded car or trailer that’s being towed.

It’s important to weigh your full set-up and make sure you stay under your GCM.

GCM = Maximum Allowable Weight of Motorhome + Trailer
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How to Weigh Your Motorhome

Weighing Your Empty Motorhome (Tare)

An important caveat with tare weight is that once you start to add permanent accessories and modifications to the motorhome, your “empty” tare weight will now be higher than what it was originally.

This particularly applies to older and second-hand motorhomes that are no longer stock standard.

The best way to find your motorhome’s current tare weight is to actually weigh it using a public weighbridge.

How to Weigh a Motorhome (Tare Weight)

How to measure the MOTORHOME TARE:

  1. Ensure the motorhome is empty of all luggage, passengers etc. and only has about 10L of fuel
  2. Drive motorhome onto weighbridge
  3. The driver must exit the motorhome and get off the weighbridge
  4. Record the weight → This is your motorhome’s tare weight
NOTE:
You can use KERB WEIGHT here, which just means weighing the motorhome with FULL FUEL TANK/S instead of trying to figure out how much 10L is.
Then, when you’re working out how much payload weight you’ve got left for your “stuff,” you know you’ve already accounted for the fuel.

Weighing Your Full Motorhome (GVM)

Once your motorhome is loaded up and ready for travel, it’s time to weigh it and make sure that you’re under your GVM (maximum allowable fully loaded weight).

This fully loaded weight must include full fuel tank/s, full water tanks, passengers, driver, food, luggage, camping gear, accessories and so on.

How to Weigh a Motorhome (GVM Weight)

How to make sure you’re under your MOTORHOME GVM:

  1. Ensure the motorhome is fully loaded and ready for travel
  2. Drive the motorhome onto the weighbridge
  3. Record the weight
  4. This needs to be lower than the manufacturer stated GVM

Weighing Your Motorhome’s GCM

If you have a trailer or vehicle being towed behind the motorhome, then you’ll need to make sure the combined weight is less than your motorhome’s GCM (Gross Combination Mass).

How to Weigh a Motorhome (GCM)

How to make sure you’re under your MOTORHOME GCM:

  1. Ensure the motorhome and trailer (or car) are both fully loaded and ready for travel
  2. Drive the motorhome and trailer onto the weighbridge
  3. Record the weight
  4. This needs to be lower than the manufacturer stated GCM

Weighing Your Motorhome’s Tow Ball Weight

If you are towing a car or trailer behind the motorhome, you’ll need to know the Tow Ball Weight, so that you can take that out of your payload allowance.

Motorhome Tow Ball Weight

How to measure the MOTORHOME TOW BALL WEIGHT:

  1. Drive only the motorhome onto the weighbridge
  2. Leave the trailer hitched up, but make sure the trailer is not on the scales
  3. Write down the weight (Weight A) → This is the motorhome’s weight including tow ball weight
  4. Unhitch the trailer off the scales
  5. Drive the motorhome only back onto the scales
  6. Write down the weight (Weight B) → This is the motorhome’s standalone weight
  7. Tow Ball Download = Weight A (motorhome weight with TBW) – Weight B (motorhome’s standalone weight)
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Motorhome Weight Calculator

Play around with the Motorhome Weight Calculator below to find out what your payload allowance will be.

This can be handy if you’re still trying to figure out which size motorhome will best suit your needs, or if you’ve already got a motorhome and want to quickly calculate payload.

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What Licence Do You Need to Drive a Motorhome?

Driver's Licence QLD (sample)
Source: QLD Government

Not all motorhomes are able to be driven on a car licence, so you’ll need to know which motorhomes you can drive with whatever licence you do have.

If you want to be able to drive larger motorhomes, RVs and buses, you will need to upgrade to a larger licence in order to stay legal.

All RV Licence Requirements →

Motorhomes up to 4.5 tonne

Anyone with a regular C class (car) licence can drive motorhomes weighing up to 4.5 tonnes GVM (Gross Vehicle Mass). The maximum number of adults your motorhome is allowed to carry is 12 (including yourself as the driver).

Motorhomes that can be driven with a C Class (car) Licence:

  • Motorhomes up to 4.5 tonne GVM
  • Motorhomes with a maximum carrying capacity of 12 adults (including the driver)

Motorhomes up to 8 tonne

To drive a motorhome that weighs from 4.5 tonne up to 8 tonne, you will need an LR (Light Rigid) licence.

With an LR licence, you can also tow a car or trailer behind the motorhome with a load of up to 9 tonnes GVM.

This is a good option for those who want to tow a little runabout car (either on or off a trailer) behind the motorhome. Many motorhome travellers like to have a secondary vehicle for when they’ve set up camp but still want the ability to explore the region.

Motorhomes that can be driven with an LR Licence:

  • Motorhomes up to 8 tonne GVM
  • Tow a car/ trailer up to 9 tonne GVM

Motorhomes over 8 tonne with 2 axles

For motorhomes that are over 8 tonne GVM, an MR (Medium Rigid) licence is required. With this licence, you can only drive a motorhome with 2 axles.

An MR licence also allows you to tow a car or trailer weighing up to 9 tonnes in total.

Motorhomes that can be driven with an MR Licence:

  • Motorhomes, RVs & Buses over 8 tonne with 2 axles
  • Tow a car/ trailer up to 9 tonne GVM

Motorhomes over 8 tonne with 3 or more axles

If you’re looking at larger motorhomes with three or more axles and a GVM of over 8 tonne, a HR licence is required. For those who want to be able to drive a full-sized bus or Big Rig, this is the licence to get.

You will also have the option of towing a car or trailer with a GVM of up to 9 tonnes.

Motorhomes that can be driven with a HR Licence:

  • Motorhomes, RVs & Buses over 8 tonne with 3 or more axles
  • Tow a car/ trailer up to 9 tonne GVM

Motorhomes over 8 tonne with 3 or more axles + trailer over 9 tonne

If, for some reason, you want to be able to tow a car or trailer heavier than 9 tonnes GVM behind your motorhome, you will need to get the largest licence available, a HC (Heavy Combination) licence.

Motorhomes that can be driven with a HC Licence:

  • Motorhomes, RVs & Buses over 8 tonne with 3 or more axles
  • Tow a car/ trailer heavier than 9 tonne GVM

Check all 30+ brands of motorhomes and campervans in Australia using the directory below.

30+ RV Brands Australia →
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Motorhomes Directory Spreadsheet

Compare all the motorhome makes, models and features with the Motorhomes Directory Spreadsheet! ↓

Motorhomes Australia Spreadsheet
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1 thought on “Motorhome Weights Explained (Calculator + How to Weigh)”

  1. Cameron Marshall

    Hi – I am enjoying the simple and well thought out information. I am yet to start my travel plans and am swamped by the types and variety of rigs….I am still tossing up between caravan, van and motor home. I also present a local radio show on ABC Mid north coast and wanted to see if you would be interested in having a sort interview. Regards Cam

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