Towing calculator
Can my car tow my caravan?
The tow rating alone does not answer that question. A legal combination has to clear four limits at once: the braked tow rating, the vehicle's GVM including ball weight, the GCM for vehicle and trailer together, and the tow ball limit. Enter the numbers from your compliance plate and your van's plate, and this checker does the arithmetic.
Your vehicle
Enter at least the braked towing rating, the GVM, and either the kerb weight or the payload. GCM and ball limit sharpen the answer when your plate lists them.
Where to find your numbers
The vehicle's figures are on its compliance or tyre placard (usually in the driver's door jamb or under the bonnet) and in the handbook; the braked towing and ball limits are in the handbook's towing section. Your caravan or trailer's ATM is stamped on its own compliance plate, normally on the drawbar. Weigh the loaded rig at a public weighbridge if you want certainty rather than paperwork.
What GVM, GCM, ATM and TBM mean
- GVM (gross vehicle mass)
- The most the vehicle itself may weigh fully loaded: the car, everyone in it, all cargo and the ball weight of a hitched trailer.
- GCM (gross combination mass)
- The most the vehicle and trailer may weigh together, both fully loaded.
- ATM (aggregate trailer mass)
- The total mass of the loaded trailer, including the share that rests on the tow ball. Tow ratings are quoted against ATM.
- GTM (gross trailer mass)
- The loaded trailer's mass through its own wheels once hitched: ATM minus the ball weight.
- TBM (tow ball mass)
- The downward load the coupling puts on the tow ball. It rides on the vehicle, so it counts toward GVM.
- Kerb weight
- The vehicle as delivered, typically with fluids and a full tank, before people, cargo and accessories.
- Payload
- GVM minus kerb weight: everything you may add, including occupants, cargo, accessories and ball weight.
This checker works off the numbers you enter; the compliance plates and handbook of your exact vehicle and trailer govern. In Australia, trailers over 750 kg GTM need their own brakes, and over 2,000 kg they need brakes on all wheels plus a breakaway system. Ball weight typically runs 8 to 12 per cent of ATM. Axle loads, tyre ratings and aftermarket GVM upgrades are not modelled.