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Most portable kerosene heaters with a roughly 1-gallon tank run about 12 to 14 hours on a full tank at a mid-range wick setting. A larger convection heater with a bigger tank can run longer. Your exact run time depends on the heater’s BTU output, its tank capacity, and the wick setting you use.
The Formula Behind This
Kerosene holds roughly 135,000 BTU per gallon, more energy-dense than propane’s roughly 91,500 BTU per gallon. A heater’s actual run time comes down to its tank capacity and its BTU output at your chosen setting: divide the tank’s total BTU capacity by the heater’s hourly BTU consumption at that setting to estimate hours of run time.
Why Wick Setting Changes the Number Significantly
Running a wick heater on a lower flame setting stretches a tank considerably further than running it at maximum output, often by several hours across a full tank. This is a bigger factor with kerosene wick heaters than with most propane models, since the flame height is directly adjustable rather than tied to a fixed BTU rating.
Tank Size Varies More Than With Propane
Unlike propane, which comes in a few standard cylinder and tank sizes across brands, kerosene heater tank capacity varies more by model. Check your specific unit’s tank capacity in its manual rather than assuming a standard figure, since it directly changes how the run-time math works out for your heater.
Does Wick Condition Affect Run Time?
Yes, indirectly. A worn or improperly trimmed wick burns less efficiently, which can mean more visible flame height for the same actual heat output, using fuel faster for a given comfort level. Our wick replacement guide covers when and how to replace one.
Does Fuel Grade Affect Run Time?
Fuel grade affects odor and burn cleanliness more than run time directly, but a wrong-grade fuel can affect how evenly the wick burns, which indirectly affects real-world efficiency. Our kerosene vs. 1-K fuel guide covers which grade your heater needs.
The Bottom Line
Expect roughly 12 to 14 hours from a full tank on a typical 1-gallon portable kerosene heater at a mid-range setting, with real variation based on your specific model’s tank size, BTU output, and wick condition. Check your manual for the exact tank capacity to refine that estimate for your heater.