Turn last winter's gas, electric, propane or oil use into this winter's heating bill – and see what the same heat would cost with a heat pump or another fuel.
By TanLabs Editorial Team · Reviewed: page results cross-checked against the free spreadsheet · Last updated · Runs in your browser – nothing you type is sent anywhere
With what heats your home now: natural gas furnace or boiler, fuel used for heat last winter 600 therms, kWh or gallons, natural gas price 1.5 $ per therm, electricity price 17 ¢ per kWh, propane price 2.8 $ per gallon, heating oil price 3.8 $ per gallon, gas furnace efficiency 90%, heat pump seasonal efficiency 2.5 COP, propane furnace efficiency 90%, oil furnace efficiency 85%:
Heating cost: $900.00 a winter (about $180.00 a month over 5 months)
54.0 million Btu of heat delivered · $16.67 per million Btu · cheapest at these prices: Natural gas ($900.00)
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Heat delivered (Btu) = fuel used × heat content per unit × efficiency. Heat content (EIA): natural gas 100,000 Btu per therm, electricity 3,412 Btu per kWh, propane 91,452 Btu per gallon, heating oil 138,500 Btu per gallon. Cost with any fuel = heat delivered ÷ (heat content × efficiency) × price per unit. A heat pump's efficiency is its COP (2.5 = 250%).
Formula source: Heat content of fuels from the U.S. EIA (100,000 Btu/therm, 3,412 Btu/kWh, 91,452 Btu/gal propane, 138,500 Btu/gal heating oil) × appliance efficiency. U.S. EIA – British thermal units (heat content of fuels) · U.S. EIA – energy conversion calculators · U.S. EIA – heating oil and propane update
Written and checked by the TanLabs Editorial Team · Last updated
Gas $1.50/therm, electricity 17¢/kWh, propane $2.80/gal, oil $3.80/gal:
| Heat needed (same heat with each option) | Natural gas (90%) | Electric resistance | Heat pump (COP 2.5) | Propane (90%) | Heating oil (85%) |
|---|---|---|---|---|---|
| Small home: 400 therms of gas | $600 | $1,794 | $717 | $1,225 | $1,162 |
| Average home: 600 therms of gas | $900 | $2,691 | $1,076 | $1,837 | $1,743 |
| Large or cold-climate home: 900 therms | $1,350 | $4,036 | $1,614 | $2,756 | $2,615 |
At these prices natural gas is cheapest, a heat pump is close behind, and electric baseboard heat costs about three times as much as gas for the same warmth.
Your utility bill or online account shows therms or kWh per month. Add the winter months and subtract a typical summer month for water heating and cooking. For propane or oil, add up the delivery tickets.
It depends on the price ratio. With 17¢ electricity, a heat pump with a seasonal COP of 2.5 costs about $20 per million Btu of heat, while gas at $1.50 per therm in a 90% furnace costs about $17. Cheaper electricity or pricier gas tips it the other way.
Check the furnace label: AFUE 80% for older or mid-efficiency units, 90–98% for condensing furnaces. Heat pumps average a COP of about 2–3 over a cold winter, lower in very cold climates.
It varies widely with climate, home size, insulation and fuel. Use your own fuel use from last winter – that already reflects your home and weather.
Turning the heat down at night or while you are out reduces the hours your system runs. Enter a lower fuel use to see how much each 10% saves.
They are delivered fuels with higher costs per unit of heat than piped gas in most areas, and prices rise in cold snaps. The EIA publishes weekly prices during the heating season.
Sources: U.S. EIA – natural gas monthly (residential prices) · U.S. EIA – heating oil and propane update · U.S. EIA – use of energy in homes