Towing capacity: how to work it out

Towing capacity: how to work it out
Towing capacity is a weighty issue - many best-selling cars are capable of towing a caravan but how do you work out how heavy a caravan or trailer they can tow?

In this guide, we look at what towing capacity is, how to work it out and the rules you need to abide by when looking to legally tow using your vehicle. 

How do I work out my car’s towing capacity?



Towing capacity is the maximum weight a car can tow legally. However, it may not be safe or comfortable to do so, especially with a caravan or trailer that has a large box-like profile.

The towing capacity may be published within the handbook of the vehicle. It can also be calculated from the VIN plate, where line one is the maximum allowable mass and line two is the maximum trian mass. Simply deduct line one from line two and you have the vehicle towing limit.

For safe towing it is recommended by many towing experts that a novice should keep the fully laden weight of the caravan no heavier than 85% of the kerbweight of the tow car. This is known as the 85% rule. Bear in mind that it is a guide and not legally enforceable.  

To calculate this, you only need to know two key figures: the kerbweight of the car and the maximum mass of the caravan (called ‘maximum technically permissible laden mass’, or MTPLM).

If the mass of the caravan is 85% or less of the car’s kerbweight, the car will tow it with ease.

If it’s between 85% and 100%, be careful – only experienced caravanners should use that car to tow such a heavy van.

But if the caravan is heavier than the car, then it is strongly recommended not to use it to tow that caravan. This calculation is known by experts as ‘outfit matching’.

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What is the kerbweight of my car?

You can find the kerbweight of your car in the owner’s manual, sometimes on a plate on the door sill or sometimes on the V5 registration document (look for the figure ‘G: Mass In Service’).

What is the weight of my caravan?

The weight of the caravan is usually listed on a plate near the door frame and in the owner’s handbook, but the manufacturer should also be able to tell you.

What else do I need to know about towing a caravan?

You also need to make sure that the maximum width of the trailer does not exceed 2.55 metres, and the maximum length of the trailer does not exceed 7 metres body length.

This length does not include the draw-bar or A-frame towing coupling at the front.

Do I need a towing licence?

All car and trailer driving tests stopped as of 20 September 2021, as the DVSA began to rollout changes to driving licences.1 Plans to allow all drivers to tow trailers with a maximum authorised mass (MAM) of up to 3,500kg were scheduled for 15 November 2021 but have been delayed until later in the year.2 

All new photocard licences will show that the BE category has been added to your licence without the need to take a test.

Previously, drivers who passed their driving test from 1 January 1997 faced tighter towing restrictions.

For further advice on towing, including useful tips on how to tow and trailer licences, read our complete guide to towing a caravan

What are the best cars for towing a caravan?

Best cars for towing a caravan

Not every car is capable of towing a caravan, especially smaller cars - and you can forget about your hatchback being up to the challenge.

If you're still unsure about what car to use or you know your car is not suitable then it is well worth researching what cars can best tow a caravan.


If you need any accessories for your caravan, be sure to have a look at our range of caravan accessories over at the RAC Shop.



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^£11 a month is for existing Camping and Caravanning Club members purchasing new personal based Caravan or Campervan Standard cover only on a monthly renewing contract. Personal based Motorhome standard cover from £12 a month.

^£11 a month for existing Camping and Caravanning Club members purchasing new personal based Caravan Standard cover only on a monthly renewing contract. Vehicle based cover from £10 a month. New member personal based prices from £16 a month.