Question: Howdy - We have an oil-burning stove in our cabin. It is approximately 4 ft high by 5 ft wide by 3 ft deep. Inside it has 2 round tanks. You can light one or both tanks to provide heat. This is an old model, and heat simply radiates from it (no fan.) What I'm trying to get a handle on is the BTUs this generates, and how a wood burning stove would compare. I'd much rather have a wood burner in there for a lot of reasons - however I want to be reasonably assured that I'd get the same (or more) heat from a stove as this old thing. Answer: The easiest way is to work backwards from how much oil it uses. Oil contain 140,000 BTU per gallon. If the unit is vented, you can assume about 60% efficiency, so you'd see about 85,000 BTU in the home for each gallon burned. If it took 4 hours to burn a gallon, then you are operating at just over 20,000 BTU/Hour output.