Learning how to weigh a caravan is an essential aspect of caravan ownership. You need to know the weight of your caravan to ensure that it is within safe limits when traveling on the road.
Although I’m new to caravanning, I have done so much research on this topic after putting down a deposit for a 22’6 Vacationer Rough Rider last year. I dove deep into understanding everything I’ll need including buying the right tow vehicle to tow our caravan.
I learned that an overweight caravan can pose a significant risk and could lead to accidents, and damage to a caravan. Additionally, if your caravan is overweight and you’re in an accident your insurance may not be covered.
This article provides an in-depth guide on how to weigh a caravan and important terms related to caravan weight.
Why Weighing Your Caravan Is Important
Weighing your caravan is important because it ensures that you are within safe limits when traveling on the road. Overloading your caravan can cause damage to the vehicle, create a potential hazard for you and other road users, and invalidate your insurance policy.
An overloaded caravan can also cause significant wear and tear on the tires, brakes, and suspension, leading to costly repairs. It can also cause instability when driving, especially at high speeds or in windy conditions.
By weighing your caravan, you will know the weight of the tow vehicle and the payload too, ensuring that you do not exceed the safe limits.
Important Caravan Weight Terms
Before delving into how to weigh your caravan, it is important to understand some of the key weight terms associated with caravans. These include:
Gross Trailer Mass (GTM)
This is the weight of the fully-loaded caravan when it is hitched to the tow vehicle. It includes the weight of the caravan and its payload.
Gross Vehicle Mass (GVM)
This is the maximum weight that the tow vehicle is allowed to weigh when it is fully loaded. It includes the weight of the vehicle, passengers, petrol, water, any cargo and the tow ball weight.
Gross Combination Mass (GCM)
This is the maximum weight that the vehicle and caravan is allowed to weigh together when they are both fully loaded. This is set by the manufacturer of your tow vehicle and can not be changed unless you do a GCM upgrade.
Aggregate Trailer Mass (ATM)
This is the maximum weight that the caravan can weigh when it is fully loaded. It includes the weight of the caravan, payload, and any water tanks.
Tow Ball Weight (TBW)
This is the weight of the fully loaded caravan on the tow ball when it is hitched to the vehicle. It should not exceed the manufacturer’s recommended limit. It is roughly 10% of the caravan’s ATM.
This TBW weight transfers from the caravan’s GTM to the tow vehicle’s GVM.
Payload
This is the weight of all the items that you carry in the caravan, including food, clothing, water and equipment.
When To Weigh Your Caravan
- When you first buy the caravan. If you can weigh your caravan as soon as you buy it this would be ideal. Then you will know your true tare weight and if it is the same as what is on the VIN plate. If you have added on extra accessories this will make your weight heavier than the tare weight on the VIN plate.
- When your caravan and tow vehicle are fully loaded. It is highly advisable to weigh your caravan after packing all the items you intend to carry on your trip. This will give you an accurate weight of the caravan and the payload. You must ensure you do not exceed your tow vehicle’s GCM.
This will ensure that the caravan is within the safe weight limits and that you are not putting yourself and other road users at risk.
- When you make any changes. Keep on top of your weight whenever you add new accessories to your caravan.
I highly recommend that you weigh your caravan before you embark on any big trip.
We will weigh our caravan on our first shake-down trip so we can get an idea of how much extra weight we can bring on our big lap.
Step-by-step Guide On Weighing A Caravan
After a lot of research, I’ve come up with the following step-by-step guide on weighing a caravan.
You will need to visit a public weigh bridge to get these weights. Best to give them a heads-up that you will be hitching and unhitching to take a bunch of different measurements.
You can make a copy of the spreadsheet we use to record your weights.
How To Measure Your Tow Vehicle’s Tare Weight
This is the weight of the vehicle without any passengers or cargo. It will include fluids and oils as well as 10L petrol.
- Ensure the tow vehicle is empty of all luggage and only has about 10L of petrol.
- Drive onto the weighbridge without the caravan.
- The driver and passengers need to get off the weighbridge.
- Record the weight
How To Measure The Caravan Tare Weight
This is the weight of the empty caravan without any payload. You can obtain this information from the caravan’s registration certificate or weigh the caravan on its own. It will also be on the caravan’s info plate. Ours is attached to the inside of the front tunnel boot.
- Ensure the caravan is empty of all food, water, luggage, gear etc
- Drive the caravan onto the weighbridge.
- Unhitch and drive the tow vehicle off the weighbridge.
- Record the weight.
How To Measure Your GVM
- Ensure your tow vehicle is fully loaded with a full tank of petrol, all passengers including the kids and any pets, and all your gear.
- Drive the tow vehicle onto the weighbridge without the caravan.
- Record the weight.
How To Measure Your GCM
- Ensure both your tow vehicle and caravan are fully loaded. This means a full tank of petrol, full water tanks, all passengers including kids and pets, and all your gear.
- Drive the tow vehicle onto the weighbridge with your caravan hitched.
- Record the weight
It is really important that you do not exceed the GCM allowed by your tow vehicle.
You may need to get upgrades done to your tow vehicle to increase the GCM. We purchased a second-hand 2021 79 series Landcruiser that already had these upgrades done. Our GCM is 7.7 tonnes. Massive!
How To Measure Your Caravans GTM
This is your fully loaded caravan weight when hitched to your tow vehicle.
- Ensure your caravan is fully loaded with full water tanks, food, and gear.
- Drive the caravan onto the weighbridge.
- Leave the caravan on the scales but drive the tow vehicle off the scales.
- Leave the caravan hitched to your tow vehicle.
- Record the weight.
How To Measure Your Caravans ATM.
This is similar to measuring your caravan’s GTM but you need to unhitch it from your tow vehicle.
- Ensure your caravan is fully loaded with full water tanks, food, and gear.
- Drive the caravan onto the weighbridge.
- Leave the caravan on the scales but drive the tow vehicle off the scales.
- Unhitch the caravan from your tow vehicle.
- Record the weight.
How To Measure The Tow Ball Weight
This requires 2 separate measurements with the tow vehicle on the scales and the caravan off the scales.
The first measurement is with the caravan hitched and the second measurement is when the caravan is unhitched.
The difference between these two measurements is the tow ball weight.
- Ensure both your tow vehicle and caravan are fully loaded.
- Drive your tow vehicle onto the weighbridge leaving the caravan off the scales.
- Take your first measurement (Weight X) with the caravan still hitched to your tow vehicle.
- Then unhitch your caravan and take your second measurement (Weight Y).
- Calculate the difference to find the tow ball weight
i.e Weight X – Weight Y = tow ball weight
How To Calculate Your Allowable Payloads
Subtract the Caravan Tare from the Caravan ATM to obtain the Payload.
Your caravan’s payload is the ATM minus the tare weight.
Your payload is everything you add to the tow vehicle and caravan.
In your caravan, it includes:
- Clothes
- Food
- Water
- Bikes
- Caravanning gear
- Cooking equipment
- Fire pit
- Outdoor mat
- Gas tanks
- BBQ
- Camping chairs
- Picnic table
- Scuba gear
Your tow vehicle’s payload is the GVM minus the tare weight.
In your tow vehicle, your payload includes:
- Caravan tow ball weight
- Full Petrol tank
- Full Water tank
- Driver & Passengers
- Recovery gear
- Fridge and food
- Roof racks
- Bull bar & tow bar
- Awning
- Roof top tent
- Tools
- Surfboard or SUP
- Tent
How To Calculate Your GVM
Add the Vehicle Tare and Payload to obtain the Gross Vehicle Mass.
How To Calculate The GTM
Subtract the Caravan Tow Ball Weight from the Caravan ATM to obtain the Gross Trailer Mass.
How To Calculate the ATM
Add the Caravan Tare and Payload to obtain the Aggregate Trailer Mass.
How To Use A Portable Weigh Scale
Portable weigh scales are available for purchase or rental from specialized suppliers. To use a portable weigh scale, place it in front of each caravan wheel and drive the caravan onto the scale one at a time.
The scale will display the weight of each caravan wheel ensuring you stay within legal limits.
Portable scales empower you with total command over the overall weight and distribution loads on each wheel. This system ensures you avoid overloading and uneven loading, which can adversely impact your driving experience.
Tips On Reducing Caravan Weight
- Reducing the weight of your caravan can be achieved by packing only the essentials and leaving unnecessary items at home. Try to adopt a minimalist lifestyle on the road. There are shops all over if you need to buy something you really need.
- Use lightweight camping gear. Every kilogram counts!
- Shift some of your payload from your caravan to your tow vehicle or vice versa. This is where knowing your weights is important! If your GVM is already near capacity you won’t be able to do this.
- Keep a spreadsheet tally of the weights of items you plan on putting in your caravan. You will be surprised how quickly things add up.
- Upgrade the GCM on your tow vehicle. This could be expensive and might not be an option if your GVM and GTM are already maxed out.
How To Weigh A Caravan FAQs
Can I Weigh A Caravan At Home?
Yes, it is possible to weigh your caravan at home using portable caravan weight scales. These are popular so you can be mindful of your weights and take extra gear out of your caravan before you leave home. They are small enough to be popped into your glove box or side door to measure your weights anytime anywhere.
You can also book a mobile service to come to your home to weigh your set-up.
Do I Have To Weigh My Caravan?
Weighing your caravan is not a legal requirement, but it is highly recommended. Overloading your caravan can cause damage to the vehicle, create a potential hazard for you and other road users, and invalidate your insurance policy. You can also be fined by police and they can ground your caravan if it is overweight.
How Can I Reduce The Weight Of My Caravan?
You may need to empty your water tanks and only fill them up at your destination. You may have to sell or give away some camping gear and only use lightweight camping gear. You could potentially shift some gear from your caravan into your tow vehicle if your weights allow it.
So Now You Know How to Weigh A Caravan To Ensure You Are Within Legal Limits
Weighing your caravan is an essential aspect of caravan ownership, as it ensures that you are within the safe weight limits when traveling on the road.
By following the step-by-step guides provided in this article, you can accurately take the different measurements required at a weighbridge and ensure you are under your GCM, GVM, and ATM.
It is also important to reduce the weight of your caravan where possible to avoid overloading the vehicle and posing a risk to yourself and other road users.