Towing Capacity Check Calculator
Check whether a planned trailer or caravan load stays within your vehicle's braked towing capacity and combined GCM limit.
Your results
Calculation breakdown
- Check 1
- Trailer weight must be ≤ vehicle's braked towing capacity
- Check 2
- Vehicle weight + trailer weight must be ≤ GCM
Worked example
A 2,800kg vehicle towing a 3,200kg trailer, with a 3,500kg towing capacity and 6,500kg GCM, gives a combined weight of 6,000kg — within both limits.
Assumptions
- Check tow ball weight separately against your tow bar's rated limit.
- Figures should come from your compliance plate and current laden weighbridge weights.
How this calculator works
Enter your vehicle's braked towing capacity, Gross Combination Mass (GCM), current vehicle weight and the trailer's actual laden weight to check whether your planned tow stays within legal limits. Exceeding either the towing capacity or GCM is illegal and can void insurance in the event of an accident.
Frequently asked questions
What is GCM and why does it matter?
Gross Combination Mass is the maximum legal combined weight of your loaded tow vehicle and trailer together; even if the trailer is under its individual limit, the combination must not exceed GCM.
Where do I find my towing capacity?
It's listed in your vehicle's compliance plate, owner's manual or manufacturer specifications, and is different for braked versus unbraked trailers.
Does trailer ball weight matter separately?
Yes, ball (tow ball) weight has its own limit, typically around 10% of trailer weight, but must also be checked against your vehicle's specific tow bar rating.