How do I find my car's maximum towing weight?

Check the VIN plate on the vehicle (usually on the driver's door frame or under the bonnet). It shows the gross vehicle weight (GVW) and gross train weight (GTW). The max towing weight is GTW minus GVW. You can also check the owner's manual or the manufacturer's website.

Noseweight is the downward force that the trailer coupling exerts on the car's towbar. It should typically be 5-10% of the total trailer weight (7% is a common target). Too little noseweight causes snaking; too much overloads the rear axle. Your towbar has a maximum noseweight rating — check the sticker on the towbar.

What is the 85% rule?

The 85% rule is a guideline (not law) that recommends the loaded trailer should weigh no more than 85% of the tow vehicle's kerb weight. Above this ratio, trailer stability decreases significantly, especially in crosswinds or at motorway speeds.

Can I tow a trailer on a car licence?

If you passed your driving test after 1 January 1997, you can tow a trailer up to 750kg MAM without extra tests. For heavier trailers, the combined MAM of vehicle + trailer must not exceed 3,500kg unless you hold a B+E (now C1E) entitlement. Drivers who passed before 1997 generally have full towing rights.

What speed limit applies when towing?

In the UK, when towing a trailer: 30mph in built-up areas, 50mph on single carriageways, 60mph on dual carriageways and motorways. You must also stay in the left lane on motorways with three or more lanes, unless overtaking.

CarCalcs

Trailer Weight Checker — Can My Car Tow This?

Check if your vehicle can legally and safely tow a trailer.

Vehicle Kerb Weight

Weight of vehicle without passengers or load

Vehicle Max Towing Weight

From VIN plate or manual

Trailer Unladen Weight

Weight or capacity related to towing

Trailer Load

Weight or capacity related to towing

Number of Passengers

Number of passengers

How We Calculate This

This calculator checks your vehicle and trailer weights against towing limits:

Total trailer weight = Trailer unladen weight + load weight
Combination weight = Vehicle (kerb + passengers) + total trailer weight
Remaining payload = Max towing weight - total trailer weight
Noseweight = Total trailer weight x noseweight percentage
Towing ratio = Total trailer weight / vehicle kerb weight x 100

A towing ratio under 85% gives the best stability. Over 100% is not recommended.

Frequently Asked Questions

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Boot Volume Calculator

Calculate usable boot space volume in litres.

Last updated: March 2026

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