Imagine you’re towing a caravan with your family on a highway. Suddenly, the trailer starts swaying violently. You hit the brakes—but the overloaded vehicle skids dangerously. The cause? Exceeding your towing limit without knowing it.
Most drivers rely on their car’s brochure towing figure—but they don’t realise it excludes passengers, cargo, and tow ball weight. The good news? Towing disasters are 100% preventable.
In this guide, you’ll learn how to calculate towing capacity step-by-step and understand critical factors like GVM, GCM, and tow ball weight. By the end, you’ll know how to tow safely, legally, and efficiently—protecting your vehicle, your cargo, and yourself.
It refers to the maximum weight a vehicle can legally and safely tow. Vehicle manufacturers determine this limit based on:
A vehicle’s rated towing ability is typically listed in the owner’s manual or compliance plate, but understanding how it is calculated ensures you don’t exceed safety limits, especially when carrying passengers and cargo.
Common Myth: “My car’s brochure says it can tow 3,500 kg—so I’m good to go!”
Reality: That number often excludes cargo, passengers, and tow ball weight, making it dangerously misleading.
Exceeding the capacity can have serious consequences, including:
A safe towing setup protects your vehicle, cargo, and other drivers on the road.
When calculating safe limits, several weight ratings play a critical role. Let’s break them down:
Why It Matters: Knowing your vehicle’s kerb weight helps you calculate how much additional cargo and trailer load you can carry before reaching GVM or GCM limits.
Tow ball weight is the downward force the trailer applies on the vehicle’s tow hitch. A tow ball weight calculator can help you quickly determine if your trailer’s download force is within the recommended range of 8–12%.
Usually, it’s 10% of the trailer’s total weight. For example, a 2,000 kg trailer = 200 kg tow ball weight. However,
When determining the right limit, always consider the combined towing weight, which includes your vehicle, trailer, passengers, and cargo. Overloading increases the risk of mechanical strain and accidents.
The basic formula is:
Towing Capacity = Gross Combination Mass (GCM) – Gross Vehicle Mass (GVM)
However, simply subtracting GVM from GCM is not enough, because it does not account for tow ball weight and payload distribution.
Check the owner’s manual or compliance plate for:
Example Calculation (Toyota Prado 150 Series):
Scenario: You’re towing a caravan with camping gear and passengers. Here’s how to calculate your actual capacity:
A caravan weight calculator simplifies this process by automatically factoring:
Penalties for towing overweight loads vary by state:
Immediate license suspension is not standard, but accumulating demerit points from overweight towing can result in license suspension, particularly for provisional drivers.
Towing beyond your vehicle’s capacity increases accident risks. Insurers may deny claims if an accident occurs under these conditions due to negligence.
If a trailer is deemed unsafe from significant overloading, authorities may impound the vehicle to prevent hazards on the road.
| Term | Definition | What’s Included |
| GVM (Gross Vehicle Mass) | Maximum permissible weight of the vehicle alone | Vehicle, passengers, cargo, fuel, and tow ball download |
| GCM (Gross Combination Mass) | Maximum allowable weight of the vehicle and trailer combined | Vehicle, trailer, passengers, cargo, and tow ball weight |
Best Practice: Keep tow ball weight between 8-12% of total trailer mass.
Selecting the appropriate trailer is crucial for staying within your vehicle’s hauling limits and ensuring safe, efficient hauling. Different types of trailers affect your vehicle’s performance, fuel efficiency, and handling, so understanding their advantages and limitations will help you make the right choice.
| Trailer Type | Advantages | Disadvantages | Best For |
| Single-Axle Trailer | Lightweight, easy to maneuver, low maintenance | Less stable at high speeds, lower load capacity | Small cargo, jet skis, utility jobs |
| Tandem-Axle Trailer | Stable on rough terrain, good for heavy loads | Heavier, reduces fuel efficiency | Caravans, boats, machinery |
| Enclosed Trailer | Protects cargo from weather and theft | Increases drag, reduces towing llimit | Furniture, motorcycles, sensitive equipment |
Understanding how to tow a car safely requires careful planning to meet legal compliance and safety standards. The towing method you choose directly affects your vehicle’s performance, handling, and braking efficiency.
A family loads their Toyota Land Cruiser with four passengers, camping gear, and a roof box—adding 450 kg to the vehicle. The vehicle’s GVM increases from 3,280 kg to 3,730 kg, reducing available towing limits and pushing it over the GCM limit.
A driver connects a 2,000 kg trailer but loads it incorrectly, placing most of the weight at the rear. The tow ball weight drops below 5%, causing dangerous trailer sway at highway speeds.
Many owners assume they can tow the maximum listed capacity without reducing vehicle payload.
Solution: Reduce cargo, roof racks, and passengers when towing heavy loads.
Unbraked trailers increase stopping distance, leading to accidents.
Legal Rule: Trailers over 750 kg must have independent brakes.
Loose cargo shifts and causes trailer sway.
Solution: Use load-securing straps and tie-down points.
Check your vehicle’s compliance plate or owner’s manual for the Gross Combination Mass (GCM) and Gross Vehicle Mass (GVM). Subtract the GVM from the GCM to estimate your towing limit.
It means your vehicle can tow up to 3,500 kg, including the trailer and its load. This figure assumes an empty vehicle—passengers, cargo, and accessories reduce the available capacity.
Subtract your vehicle’s Gross Vehicle Mass (GVM) from its Gross Combination Mass (GCM). Be sure to include the weight of passengers, cargo, and tow ball download in your calculations.
Gross Vehicle Mass (GVM) is the maximum weight your vehicle can carry, including passengers, cargo, and tow ball download. A higher GVM reduces your available hauling limits.
Tow ball weight, typically 10% of the trailer’s total weight, affects vehicle stability. Too little can cause trailer sway, while too much can reduce steering control and braking efficiency.
Exceeding the capacity can cause mechanical failures, longer stopping distances, and potential insurance claim denials. You may also face fines or vehicle impoundment for unsafe towing.
Yes, but your vehicle’s braked towing limit must exceed the towed car’s weight. Additionally, you must use ADR-approved equipment and have breakaway brakes for loads above 2,000 kg.
Gross Combination Mass (GCM) is the total allowable weight of the vehicle plus the trailer. Gross Vehicle Mass (GVM) refers to the vehicle’s maximum carrying capacity without the trailer.
Yes, trailers weighing over 750 kg require brakes. Trailers exceeding 2,000 kg must have breakaway brakes, which automatically activate if the trailer disconnects from the vehicle.
Payload, including passengers, cargo, and accessories, adds to the vehicle’s GVM. The more payload you carry, the less weight remains for towing within the GCM limit.
Towing safely means knowing and respecting your vehicle’s limits. Always check your GCM, GVM, kerb weight, and tow ball weight to avoid accidents and legal issues. Before every trip, verify that your tow ball weight is 8–12% of the trailer’s total weight and use a caravan weight calculator to factor in passengers and cargo. Secure your load properly and ensure your trailer brakes meet legal standards.
But safety isn’t just about numbers—it’s about choosing the right trailer. A poorly matched trailer can damage your vehicle and compromise safety. That’s why King Kong Trailers offers durable, road-compliant trailers designed to fit your towing capacity perfectly. Tow smarter. Tow safer. Contact King Kong Trailers today to find the best trailers for your work or leisure needs—built for performance, safety, and reliability.
Are you ready to hit the open road with your caravan but unsure about its weight? Understanding it isn’t just about compliance—it’s the key to safety, efficiency, and an enjoyable journey. Whether you’re new to caravanning or a seasoned traveler,
Towing a caravan opens up a world of exploration and adventure, allowing travellers to enjoy the flexibility of bringing their accommodation wherever they go. However, towing is not without its challenges. From understanding your vehicle’s capabilities to mastering driving techniques,
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