Motorhome payload calculator
Enter your motorhome's maximum weight (its MAM, also written MTPLM) and its mass in running order (MIRO), then the weight of what you carry. This page takes the MIRO from the MAM to give the payload, adds up your load, and shows how much is left or how far over you are. The sums run in your browser: nothing you type is sent or kept.
Calculator
On the motorhome's weight plate.
Mass in running order: the figure in your handbook.
What you carry
Rename, remove or add rows. Leave a row empty if it does not apply or your MIRO already covers it.
Enter the MAM and the MIRO to see the payload. Nothing is worked out from a figure you have not entered.
What MAM, MIRO and payload mean
- MAM. GOV.UK says maximum authorised mass means the weight of a vehicle or trailer including the maximum load that can be carried safely when it is being used on the road, and that it is also known as gross vehicle weight. The Camping and Caravanning Club says the MTPLM on a motorhome is the same figure as the MAM on its weight plate.
- Payload. The Camping and Caravanning Club says payload is considered to be the difference between the MIRO and the MTPLM, and is the weight you can put on board.
- MIRO. The club says this now varies with the maker. It says MIRO traditionally means the motorhome ready to travel, with 75kg allowed for the driver and the fuel tank 90 per cent full, and that the allowance for gas can be for just one lightweight cylinder.
Does the payload include passengers and water?
The Camping and Caravanning Club tells buyers to check that there is enough payload for the number of people and the kit they intend to carry. The one person it describes as traditionally counted in the MIRO is the driver, at 75kg.
On water, the club says a MIRO may include an allowance for fresh water: older UK motorhomes often allowed for a tank 90 per cent full, and makers now usually allow for an empty tank or one filled to 20 per cent.
It also says some converters outside the National Caravan Council's approval scheme may class payload as the difference between the MAM and the unladen weight, which leaves out fuel and the driver. So read what your own handbook says its figure includes before you fill in the rows, and leave out anything it already counts.
Fitted extras count too. The club says your available payload reduces when items are added as fitted extras.
What this calculator cannot tell you
- What your MIRO includes. That is in your handbook, and this page cannot see it.
- What the motorhome really weighs. The page adds up the weights you type. The Camping and Caravanning Club advises taking the motorhome to a public weighbridge, loaded as you would for a major trip and with your normal passengers. GOV.UK has a service for finding one.
- The axle loads. The club says each axle has its own limit, shown on the weight plate, which must not be exceeded. A load inside the payload can still put too much on one axle.
- Whether your licence covers the MAM. GOV.UK says a motorhome with a MAM between 3.5 and 7.5 tonnes needs a category C1 licence. Who holds one is in Driving a motorhome on a car licence.
If you are selling a motorhome
Put the MAM and the MIRO in the advert, so a buyer can run this sum. Listing is free. Selling your motorhome compares the ways to sell.