Fuel Cost Calculator

How It Works

Comparing heating fuels is confusing because they are sold in different units: gas in therms, electricity in kilowatt-hours, propane and oil in gallons, wood in cords. The only fair comparison is cost per million BTU of delivered heat, which accounts for both the energy content of the fuel and the efficiency of the equipment burning it. A therm of natural gas contains 100,000 BTU, but a 95 percent efficient furnace only delivers 95,000 BTU to your home. A cord of hardwood contains about 20 million BTU, but a wood stove at 75 percent efficiency delivers only 15 million. This calculator normalizes everything to the same unit so you can see which fuel is truly cheapest in your area.