If you’re new to caravanning or looking at caravans in Heatherbrae, chances are you’ve come across the term “tare weight.” It’s one of those specs that sounds simple at first, but quickly turns confusing—especially when it comes to what’s actually included in that number. A big question for many buyers is whether the tare weight of a caravan includes full water tanks.
Understanding this properly is essential for safety, compliance, and trip planning. Overloading your caravan or miscalculating payload can lead to legal issues, performance problems, or even dangerous towing conditions. So let’s clear up the confusion.
What Is Tare Weight?
Tare weight refers to the weight of the caravan as it leaves the factory, with all standard equipment fitted—but without any personal gear, optional extras, or filled water tanks. Think of it as the “empty” weight of your caravan, before you pack a single thing inside it.
According to the Vehicle Standards Bulletin 1 (VSB1), tare weight is measured with:
- All factory-standard equipment installed
- No water in the tanks
- Empty gas bottles
- No food, clothes, or camping gear
This is the benchmark manufacturers use to calculate payload and overall weight limits. But once you start adding extras or filling tanks, your total weight increases significantly.
Does It Include Water Tanks?
No. Tare weight does not include full water tanks. While your caravan may have the tanks fitted and plumbed when weighed, they will be empty during tare measurement. This is critical to understand because water is heavy—about 1kg per litre. A 120-litre water tank adds roughly 120kg to your load when full.
If you rely on the tare weight and forget to factor in full water tanks, you can unknowingly exceed your payload capacity or even your maximum ATM (Aggregate Trailer Mass).
Why Does This Matter For Towing?
When you’re planning a trip, knowing your weights helps ensure you’re towing within legal and safe limits. Exceeding your caravan’s ATM or your vehicle’s towing capacity can:
- Void your insurance
- Get you fined during roadside checks
- Reduce braking performance
- Lead to increased wear and tear
- Risk sway or loss of control on the road
Always calculate your full load, including water, gas, food, gear, and passengers. It’s not just about legality—it’s about keeping you and your family safe.
Understanding Payload and Water Weight
Your payload is the difference between your caravan’s tare weight and its ATM. For example, if your caravan has a tare of 2200kg and an ATM of 2800kg, your payload is 600kg. That sounds like plenty until you do the maths:
- Water tank (120L): 120kg
- Gas bottles (2 x 9kg): 18kg
- Clothes, food, utensils: 150kg
- Camping gear, chairs, tables: 60kg
- Solar panels, batteries: 100kg
That’s nearly 450kg right there—and you haven’t packed your fishing gear or wine fridge yet. Being mindful of water weight alone can help you avoid running into trouble.
Wet Weight Vs Dry Weight
You might hear the terms “wet weight” and “dry weight” tossed around. These are more common in motorbike or marine contexts, but sometimes used informally in caravanning too.
- Dry weight: Same as tare—empty tanks, no gear
- Wet weight: Tare plus full water and gas
Manufacturers aren’t required to list wet weight, but some do it as an added transparency measure. Just know that official compliance labels will stick to tare and ATM only.
How Do You Know What Your Caravan Weighs Now?
The most accurate way to know your current weight—including full tanks—is to visit a public weighbridge. You can:
- Weigh the entire rig (car and van) together
- Weigh the caravan alone
- Get axle weights and ball weight separately
Do this fully loaded, with everything you’d take on a real trip. It gives you a true picture of how close you are to limits.
Don’t Rely Solely On Manufacturer Specs
Specs printed on the compliance plate may not reflect real-world conditions. If your dealer added accessories (solar panels, toolboxes, air conditioning), they may have done it after the tare weight was calculated.
Always ask for a weighbridge certificate if you’re buying second-hand or confirm that post-factory additions have been factored into the updated ATM and tare.
Can I Travel With Full Water Tanks?
Yes, but do it with care. Some travellers fill up only when needed or top up at the destination to save on towing weight. Others fill up beforehand to ensure they have clean water from a trusted source. There’s no one-size-fits-all, but consider:
- Distance you’ll travel
- Weight impact on tow vehicle
- Access to water where you’re headed
If you plan your loads smartly, you can safely travel with full tanks—just account for the weight properly.
Frequently Asked Questions
1) How Much Does Caravan Water Weigh?
Water weighs approximately 1 kilogram per litre. So if your caravan has a 100-litre water tank, that’s 100 kilograms added to your total weight when full. It adds up fast, especially when you consider that many caravans come with multiple water tanks—fresh water, grey water, and sometimes even black water tanks. For example, a van with two 90-litre tanks could be carrying 180kg in water alone. Always include this in your calculations, particularly if you’re towing near your legal limit. Forgetting to account for water weight is one of the most common mistakes new caravanners make, and it can easily tip you over your ATM without you realising it.
2) Is It Illegal To Exceed Your Caravan’s ATM?
Yes, it is. Exceeding your caravan’s ATM is a breach of road safety laws in every Australian state and territory. If caught at a roadside check or involved in an accident, it could lead to fines, demerit points, or worse—insurance refusing to pay out. Even if you’re just a few kilograms over, enforcement officers won’t make allowances. It’s your responsibility to know and stay within your weight limits, which means including the weight of full water tanks, gas bottles, and all loaded gear. Regular trips to a weighbridge and smart packing can help you stay compliant and safe.
3) Do Dealers Tell You The Tare Weight With Extras Installed?
Not always. Tare weight shown on the compliance plate is meant to reflect the factory condition, without any dealer-fitted extras. If your caravan was upgraded with solar panels, extra water tanks, toolboxes, or upgraded appliances after leaving the manufacturer, those additions are not included in the listed tare. This can be misleading. Some honest dealers will re-weigh the van and provide a new certificate showing the updated weight, but it’s not a legal requirement. That’s why it’s important to ask specific questions and, if necessary, get it weighed yourself before setting off.
4) Should I Travel With Full Or Empty Water Tanks?
It depends on your travel style. Travelling with full water tanks offers flexibility and peace of mind, especially if you’re heading to remote or off-grid locations. But it adds significant weight, which impacts fuel consumption, handling, and towing stress. If you’re sticking to caravan parks or known areas with water access, you can travel light and fill up later. Some caravanners split the difference—starting with a half tank to keep weight down while still having some water on hand. The key is to balance your load and ensure you remain under your weight limits either way.
5) What’s The Best Way To Weigh My Caravan Fully Loaded?
The best way is to use a certified public weighbridge. Drive your fully packed caravan (with your tow vehicle, if possible) onto the platform and get readings for:
- Gross weight (van and car combined)
- Caravan only
- Tow ball weight
- Axle weight distribution
Some weighbridges charge a small fee, but the insights are worth it. You’ll know whether you’re within your legal limits and where you might need to cut back. Take note of your weights with and without water to see the difference. Keeping a record each trip helps you learn what works and stay consistent.
Speak With The Local Experts At 7th Street Caravans
If you’re uncertain about towing weights or just need help navigating specs and water storage, the team at 7th Street Caravans are here to help you travel smarter.
Start your journey with confidence — visit 7th Street Caravans or give our team a call on 02 4012 6009 for friendly, local advice.