Caravan towing weight calculator
Enter your car’s weights and the caravan or trailer’s maximum weight. You’ll see whether the outfit is within the legal limits and the 85% guideline, and the heaviest caravan that fits.
- Rules for Great Britain
- Figures checked 25 October 2026
- You’ll need the car’s handbook or VIN plate, and the caravan’s weight plate
Your result
Enter the trailer weight.
The limits that apply
Four separate numbers decide whether a car can tow a caravan or trailer. Three are legal limits; the fourth is long-standing safety advice.
- The car’s towing limit. Set by the manufacturer, braked and unbraked. The trailer’s maximum weight must not go over it.
- Gross train weight. The car fully loaded plus the trailer fully loaded must not go over it. The calculator uses the car’s MAM, which is the worst case.
- Your licence. If you passed your test from 1 January 1997, you can tow a trailer up to 3,500kg MAM (category BE). If BE isn’t shown on your photocard yet, DVLA adds it when you next renew. Licences from before 1997 usually cover a combined weight up to 8,250kg.
- The 85% guideline. Keep the loaded caravan at or under 85% of the car’s kerb weight for stable towing, especially if you’re new to it.
Unbraked trailers have an extra legal limit of 750kg or half the car’s kerb weight, whichever is lower. Caravans and trailers up to 2.55m wide can be towed by cars.
Worked example
A car with a 1,550kg kerb weight, an 1,800kg braked towing limit, a 2,100kg MAM and a 3,900kg gross train weight, towing a 1,400kg caravan. The caravan is within the towing limit, and 2,100kg plus 1,400kg is 3,500kg, within the train weight. But 1,400kg is 90% of the kerb weight, over the 85% guideline. The heaviest caravan inside 85% is 1,317kg.
Questions people ask
What is the 85% towing rule?
It’s advice, not law. Towing experts recommend that a loaded caravan weighs no more than 85% of the tow car’s kerb weight, so the car stays in charge of the caravan. Experienced towers sometimes go up to 100%, but never above the car’s legal towing limit.
Can I tow a caravan on a normal car licence?
If you passed your test on or after 1 January 1997 you can tow a trailer up to 3,500kg maximum authorised mass (category BE). If you passed before 1997 you can usually drive a car and trailer combination up to 8,250kg.
How heavy can an unbraked trailer be?
No more than 750kg, or half the towing car’s kerb weight if that is lower. Check the car’s unbraked towing limit too, as some are lower still.
What is gross train weight?
The most the car and trailer together may weigh, including passengers, luggage and the loaded trailer. It is on the car’s VIN plate, usually as the second weight listed, and in the handbook.
Where do I find my caravan’s weight?
Use the MTPLM (maximum technically permissible laden mass) on the caravan’s weight plate, usually near the door. It is the most the caravan may weigh when loaded.