Caravan Payload Calculator

MTPLM stands for Maximum Technically Permissible Laden Mass — the maximum legal weight your caravan may reach once fully loaded, including its own weight, the items you pack, water and gas. It's stamped on the caravan's VIN/weight plate, usually near the A-frame or inside a locker.

MRO (Mass in Running Order) is the caravan's weight as built, before you add your own belongings. Under NCC Code of Practice 304, MRO already includes an allowance for one gas cylinder (about 10 kg) and the mains hook-up lead (about 4 kg), per Coachman's explanation of MRO, MTPLM and User Payload.

Subtract MRO from MTPLM — both figures are on your caravan's weight plate. In the tool's overloaded worked example, 1,500 kg MTPLM minus 1,350 kg MRO gives 150 kg of available payload, which a full water tank, a spare gas bottle, a battery, an awning, bikes and normal kit can easily exceed.

Not always. Some brochures quote a lighter "shipping weight" that excludes items your caravan actually carries as standard. Always use the MRO figure stamped on your caravan's own weight plate, not a brochure figure, when working out real payload.

A typical UK touring awning weighs 25–35 kg, according to Out and About Live's caravan weights and payloads guide — often one of the single biggest items in a packing list, alongside a full water tank.

A typical 100Ah AGM leisure battery weighs about 28–30 kg, while an equivalent 100Ah lithium (LiFePO4) battery weighs about 14–15 kg, per Practical Caravan's leisure battery buying guide. Switching to lithium can free up meaningful payload if your current MRO doesn't already include a battery.

Yes, in full — MRO calculates the fresh water tank as empty, so every litre you fill counts as extra weight at 1 kg per litre. A 40-litre tank filled to the brim adds 40 kg; many experienced caravanners travel with a part-full tank (10–20 litres) and top up on arrival specifically to save payload for other items.

Your first gas cylinder is already included in MRO's standard allowance (about 10 kg, or 20 kg with a twin-cylinder Duo Control/Comfort regulator). Only a spare or second bottle — a full 6 kg propane cylinder weighs roughly 15–17 kg gross, per MotorhomeFun's cylinder weight thread — needs to be added as extra payload in this tool.

No. It is against UK towing law for anyone to travel inside a caravan, horsebox or trailer while it is being towed — every passenger must travel in the tow car, properly seated and belted, according to nidirect's towing safety information. This tool has no passenger-weight field for that reason; passenger weight belongs in your tow car's own payload calculation.

GOV.UK's Highway Code rule 98 states you MUST NOT overload your vehicle or trailer. Beyond the legal requirement, an overloaded caravan handles unpredictably, brakes worse and can snake at speed. If the tool shows you're over, start by removing or reducing your single heaviest item — often the water tank or the awning — and recheck.

It means you're using 90% or more of your available payload but not yet over it. There's little margin left for extra shopping, wet clothing on the way home, or anything you forgot to weigh — worth trimming a few kilograms before you set off rather than cutting it exactly to the limit.

No. Payload is your caravan's total weight allowance; noseweight is how much of your packed load presses down on the tow hitch, which depends on where you position items, not just how much you carry. Use CoryVu's Caravan Noseweight Calculator alongside this tool — a caravan can pass one check and fail the other.

It's only as accurate as the weights you enter. Item weights (awning, battery, water) are reasonable planning estimates, but the only way to confirm your actual loaded weight is a public weighbridge check with the caravan packed exactly as you intend to travel — many caravan clubs and some fuel stations offer this.

Because no one is legally permitted to travel inside a caravan while it is being towed in the UK, per nidirect's towing guidance. Any passengers and their belongings should be weighed against your tow car's own payload capacity, not the caravan's.

No — a roof box, bike rack or any load fitted to the tow car itself counts against the car's own kerb weight and payload limits, not the caravan's MTPLM/MRO figures used in this tool.