Caravan Gas Bottle Duration Calculator

Most touring caravans and motorhomes use a 6 kg propane bottle for short trips, or a 13 kg propane bottle for trips of a week or more or heavier appliance use, according to Adams Gas's cylinder-size guide. A 19 kg propane bottle is heavier and generally suits static caravans or very long stays rather than regular touring.

Propane keeps vaporising down to about -42°C, so it works reliably through a UK winter. Butane stops vaporising reliably below about -2°C, so it is only suitable for spring, summer and mild-weather trips. Propane's energy content (14.02 kWh/kg, per Flogas) is also slightly higher than butane's (about 13.7 kWh/kg).

The only reliable method is to weigh the bottle on a set of scales and subtract the empty "tare" weight stamped on the collar near the valve. Shaking, listening for sloshing, or checking with a magnetic level gauge can give a rough sense but are not precise, especially as a bottle nears empty.

It depends entirely on what you run. In the tool's shortfall worked example — 1.5 hours of hob use, 4 hours of Medium heating, a standard gas fridge and 1 hour of hot water a day — a full 6 kg bottle lasts about 4.1 days, short of a 7-day trip. Cut the heater to Low and skip the gas fridge and the same bottle can comfortably last 10 days or more.

A Truma S3004 space heater (3.5 kW) uses 30–280 g/h depending on the thermostat setting, and the larger S5004 (6 kW) uses 60–480 g/h, according to Truma's own product specifications. This tool uses 60 g/h for Low, 180 g/h for Medium and 380 g/h for High as representative figures across that range.

A standard 3-way caravan fridge uses roughly 200 g of gas a day when run continuously at around 25°C ambient temperature, and a large fridge-freezer such as the Dometic RMD 8555 can use closer to 380 g/day, per Caravan Helper's fridge gas-use guide. Switching to electric hook-up or 12V power can meaningfully extend a bottle's life.

It's a safety margin, not a manufacturer rule: the tool flags when your remaining gas drops to 20% of the bottle's nominal weight so you have time to swap or refill before you're caught with an empty bottle. For a 6 kg bottle that's 1.2 kg remaining; for a 13 kg bottle, 2.6 kg.

Yes, as long as your gas locker and regulator support the larger cylinder's footprint and connection — most touring caravan lockers are sized for 6 kg or 7 kg bottles, so check the locker dimensions before buying a 13 kg or 19 kg cylinder. A 13 kg propane bottle refills at roughly £3.50/kg against about £4.78/kg for a 6 kg bottle.

There's no way to measure your exact real-world consumption without a flow meter, so this tool uses each appliance's manufacturer-published rated consumption at a given setting, which tends to be a conservative (higher) figure than typical thermostat-cycled use. The duration shown is usually a safe minimum rather than an exact prediction.

Industry guidance points to a 10-year replacement interval for both the regulator and the hose, regardless of visible condition, because the rubber and seals age even when the system isn't heavily used (see GOK's regulator and hose guidance). UK caravan LPG systems typically run at 30 mbar.

Turn off the gas at the bottle, extinguish naked flames, open windows and vents, and do not use electrical switches until the smell has completely cleared. The HSE's guidance on LPG covers the risks of LPG leaks and ignition sources in more detail. Have the system checked by a Gas Safe registered engineer before using gas appliances again — this tool is a planning estimate, not a safety check.

Yes, in two ways. Butane can stop vaporising below about -2°C, effectively cutting off supply regardless of how much liquid gas remains. Propane keeps working down to about -42°C, but a caravan heater typically runs for longer each day in cold weather, which increases the daily gas total once you enter more heater hours.

If the calculator shows your trip length is close to or beyond the days remaining — especially in the amber or red assessment bands — a second bottle plumbed through a changeover valve, or a spare bottle you can swap in manually, removes the risk of running out mid-trip.

In the tool's two worked examples, daily gas cost is about £7.01 for the heavier four-appliance day (6 kg propane at roughly £4.78/kg) and about £2.45 for the lighter day (7 kg butane at roughly £5.51/kg). The heater is usually the single biggest cost driver.

No. This is an independent CoryVu calculator built from publicly published Calor, Flogas and Truma specification and pricing pages, checked on 2026-08-30. For your specific cylinder, appliance or system, always check the manufacturer's data plate and current retailer pricing.