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Heating fuel cost comparison ($/MMBtu)
Delivered-heat cost per million Btu, ranked across fuels.
Heat content per unit, from the EIA energy conversion tables: propane 91,452 Btu/gal, No. 2 heating oil 138,500 Btu/gal, natural gas 100,000 Btu/therm, electricity 3,412 Btu/kWh. Efficiency is the share of that heat delivered to the room; the defaults (90% propane, 85% oil, 92% gas, 100% electric resistance) are typical mid-range appliance figures, editable above — a heat pump delivers 200-300% and is entered as such. The result is a per-MMBtu cost of delivered heat; local prices, taxes, and equipment vary.
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Common questions
Is propane or heating oil cheaper per Btu?
It depends on the local price of each and your appliance efficiencies. This tool converts both to dollars per million Btu of delivered heat so they compare on the same basis — enter your prices above.
How do you compare propane, gas, oil, and electricity?
Convert each fuel's price to the cost of a million Btu using its heat content, then divide by the appliance's efficiency to get the cost of delivered heat. The lowest dollars-per-MMBtu is the cheapest heat.