BTUs or British Thermal Units, are the measure of heat the stove is capable of emitting. For a group of 2-4 campers, you’ll want something in the neighborhood of 10-20,000 BTUs. For larger groups, you’ll want to ramp that up to 20-30,000 BTUs. But keep in mind that efficient outdoor cooking is not just a matter of throwing BTUs at the problem. Wind is the enemy of outdoor cooking and the fact is that a 10,000 BTU outdoor stove that has effective windscreens will likely boil water faster than a 30,000 BTU camping stove with no windscreens.\r