Home energy · heating costs
Heating cost per GJ, fuel against fuel.
Gas, propane, oil, electricity, a heat pump and wood, all converted to cost per GJ and per kWh of heat delivered. You supply the prices; nothing leaves your browser.
Prices and efficiencies
Fill in only the heat sources you are weighing. Rows left blank are skipped.
Cost of delivered heat
How it works
For each source: cost per kWh of delivered heat = price per unit ÷ (kWh of energy per unit × efficiency). Cost per GJ = cost per kWh × 277.78 (1 GJ = 277.78 kWh, since 1 kWh = 3.6 MJ). For the heat pump, the efficiency is its COP (a COP of 2.5 means 250% efficient) and the price is the electricity price you entered. Annual cost = cost per GJ × delivered heat in GJ.
Energy content used
Natural gas 1,036 Btu per cubic foot (about 10.72 kWh per m³); propane 91,452 Btu per US gallon (about 7.08 kWh per litre); heating oil 138,500 Btu per US gallon (about 10.72 kWh per litre); wood 20,000,000 Btu per cord (about 5,862 kWh); electricity 3,412 Btu per kWh; 1 therm = 100,000 Btu. Unit conversions: 1 US gallon = 3.785411784 L, 1 m³ = 35.3146667 ft³.
Worked example
Illustrative prices only, not market data: heating oil at $1.50 per litre in an 85%-efficient furnace. Oil carries 138,500 ÷ 3,412 ÷ 3.7854 = 10.72 kWh per litre, so delivered heat costs 1.50 ÷ (10.72 × 0.85) = $0.165 per kWh, about $45.71 per GJ. Electricity at $0.14 per kWh through a heat pump with a seasonal COP of 2.8 costs 0.14 ÷ 2.8 = $0.05 per kWh, about $13.89 per GJ, while the same electricity in baseboards costs $0.14 per kWh (about $38.89 per GJ). A home needing 80 GJ of heat a year would pay about $3,657 for the oil and $1,111 for the heat pump on those assumed prices.
Sources and as-of date
U.S. EIA, British thermal units (Btu) heat content table (natural gas, propane, heating oil, wood, kWh and therm values; page opened 2026-10-01). These are U.S. reference averages; actual fuel energy content varies by supplier, and Canadian supplier bills may state their own. The EIA page shows no revision date.
No prices or efficiencies are built in, because rates change by region and month and equipment varies. This is a planning estimate, not a quote or engineering advice.
FAQ
Why compare per GJ or kWh of delivered heat?
Fuels are sold in different units (cubic metres, litres, gallons, cords, kWh). Dividing price by the energy in a unit gives cost per unit of fuel energy; dividing again by efficiency gives cost per unit of heat that actually reaches the house, which is the fair basis for comparison.
What efficiency should I use?
Use the rating on your equipment: AFUE for furnaces and boilers, a seasonal COP for a heat pump, 100% for electric resistance at the point of use. A rated figure is a laboratory or test-procedure number; installation, ducts and climate change real results.
Why does a heat pump often win against electric resistance?
Resistance heat delivers at most 1 kWh of heat per kWh of electricity. A heat pump moves heat and delivers COP kWh per kWh, so at the same electricity price its heat costs 1/COP as much.
Are these energy contents exact for my fuel?
They are U.S. EIA reference values. Actual natural gas, propane and oil vary by supplier, and wood varies a lot by species and moisture. Natural gas bills in GJ need no conversion, which is why GJ is offered as a price unit.
Does the result include equipment, maintenance or carbon charges?
No. Only fuel or electricity cost per unit of delivered heat. Add delivery fees, fixed monthly charges and any carbon pricing to the price you enter if they apply to your bill.