What is the 85% rule?

For safe, stable towing, the loaded trailer weight should not exceed 85% of your car's kerbweight. While legally you may tow more (up to the car's rated maximum), exceeding 85% makes the outfit harder to control, especially in crosswinds.

What can I tow on a normal licence?

If you passed your test after 1 January 1997, you can tow a trailer up to 750kg, or a heavier trailer as long as the combined MAM of car + trailer does not exceed 3,500kg. Drivers who passed before 1997 can tow up to 8,250kg combined.

Where do I find my car's towing limit?

Check the V5C (logbook), owner's handbook, or the VIN plate on the car. The manufacturer's website also lists towing weights. There are separate limits for braked and unbraked trailers.

What is the difference between braked and unbraked towing?

Braked trailers have their own braking system activated by the car. Unbraked trailers rely solely on the car's brakes. The unbraked towing limit is much lower, typically 750kg or 50% of the car's kerbweight, whichever is less. Caravans and larger trailers always have brakes.

Do I need a special licence to tow?

If you passed your driving test after 1 January 1997, you can tow up to 3,500kg combined weight (car + trailer MAM) on a standard Category B licence. For heavier combinations, you need a B+E licence. Drivers who passed before 1997 can tow up to 8,250kg combined.

CarCalcs

Towing Capacity Calculator

Check if your car can safely tow a specific trailer or caravan.

Car Kerbweight

Max Towing Weight

From V5C or handbook

Gross Vehicle Weight

Optional — from VIN plate

Loaded Trailer Weight

Number of Passengers

Luggage Weight

How We Calculate This

Compares your loaded trailer weight against the car's maximum towing capacity and the recommended 85% kerbweight guideline.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.