Three numbers run this entire topic#
377 kilojoules. The energy needed to take one litre of water from 10 degrees C to boiling. Fixed, whatever stove you own.
334 kilojoules. The energy absorbed by one kilogram of ice as it melts. It is the whole mechanism of a cooler, and it also explains why melting snow for water costs roughly twice the fuel of heating stream water.
45.8 megajoules per kilogram. The energy in canister gas. Divide the first number by the third, allow for the fact that only a third to two thirds of the flame reaches the water, and you have your fuel requirement to the gram.
Everything else in this section is an application of those three: how much fuel to carry, which stove delivers its energy best in wind and cold, how much ice a weekend needs, and where the crossover sits between a cooler and a fridge.
Water treatment is the exception, and the one page here where the stakes are health rather than comfort. It is organised by threat class rather than by product type, because the only question that matters is which of protozoa, bacteria and viruses you are defending against.
Where to start#
- Choosing a stove: camping stove types compared
- Winter or shoulder season: canister stoves in the cold
- Planning a trip: how much stove fuel to carry and the fuel calculator
- Drinking safely: backcountry water treatment
- Keeping food cold: coolers and ice and the ice calculator
- Kit list: camp cookware that earns its weight
Frequently asked questions#
How much gas does a weekend need?#
For two people boiling about 1.2 litres each per day on an upright canister stove in light wind, roughly 100 to 140 g over two days including a margin. That is one 110 g canister if conditions are kind and a 230 g canister if they are not. The fuel calculator works it from your own menu.
Is a heat exchanger pot worth the weight?#
It roughly doubles delivered efficiency against an open burner in wind, so it pays for itself in saved fuel on trips with many boils, and never pays on a two night trip with one hot meal a day. The break-even is a fuel weight calculation, not a preference.
Do I have to filter water in the mountains?#
Clear, fast moving water high above human and livestock activity is lower risk, but risk is not the same as none, and giardia and cryptosporidium are present in remote catchments worldwide. Treat unless you have specific local knowledge, and choose the method by which threats are present.
How much ice do I need for three days?#
For a mid-range hard cooler in the shade at around 26 degrees C, expect to need roughly 1.5 to 2 kg of ice for each kilogram of food and drink over three days, more in direct sun. Pre-chilling the box and the contents removes a large slice of that.