How long does a 13 kg propane bottle last? Work it out in two minutes

The formula

Hours of use ≈ kg of gas × 13.8 ÷ gas heat input in kW. The 13.8 is an approximate energy content in kWh per kilogram of propane. Use the gas input rating, not useful heat output, from the data plate or manual; add inputs of appliances running together. Prefer the manufacturer’s stated consumption in kg/h where available.

Worked examples

For a full 13 kg bottle: a patio heater with 13 kW gas input gives roughly 14 hours at full power; a barbecue with 9 kW gas input gives about 20 hours. A caravan heater with 3 kW gas input gives about 60 hours, or seven to eight nights at eight hours per night, excluding other gas use. These are theoretical examples, not guaranteed runtimes.

Lower settings or thermostat cycling generally extend the time. Wind and cold can increase heating demand or affect gas delivery; they do not automatically increase consumption at a fixed gas input. Extra burners or appliances add to consumption.

Track your own use

The most reliable number is your own. Write the date on a label when you connect a fresh bottle and note when it runs out, or watch the level drop in a sensor app over a few weeks. After one or two bottles you will know your pattern.

Plan the swap

Once you know roughly how many days a bottle lasts, order or swap with a margin, especially in winter when exchange points can run short and use goes up.

WiseTank delivers free to the UK, usually in 7–15 working days from dispatch in China, with tracking. GBP prices are still being set, so you can reserve free with no obligation on any product page.