Heat Pump vs Furnace Cost Calculator

1. Enter your yearly heating load in million Btu (MMBtu) of delivered heat. If you do not know it, open the estimate helper and type last winter's therms or gallons and your old system's efficiency.
2. Enter your electricity price per kWh. Divide the total of your bill by the kWh used so delivery charges are included.
3. Enter the heat pump's seasonal COP, or switch to HSPF2 and type the rating from the label.
4. Pick the furnace fuel, then type your fuel price and the furnace or boiler AFUE.
5. Read the yearly cost of each system, the savings, the break-even COP and electricity price, the chart, and the working below the result.

The load is heat delivered into the house, so it is the same for both systems. Only the price of each unit of heat changes.

Each formula gives C, the cost of one million Btu of heat delivered into the home. The heat contents come from the U.S. Energy Information Administration: 1 therm = 100,000 Btu, 1 gallon of propane = 91,452 Btu, 1 gallon of heating oil = 138,500 Btu and 1 kWh = 3,412 Btu.

AFUE is written as a decimal, so 95% is 0.95. A therm is 0.1 MMBtu, which is why gas uses x 10. HSPF2 is Btu per watt-hour, and 1 watt-hour is 3.412 Btu, so dividing by 3.412 gives a unitless COP.

Q is the heating load in MMBtu. Above the break-even COP, or below the break-even electricity price, the heat pump is cheaper to run.

Each row is computed from the formulas above. The prices are the calculator defaults, recent EIA U.S. averages, and the last column assumes a 60 MMBtu yearly load.

At these prices a heat pump with a seasonal COP of 3 costs less than even a 95% gas furnace, and far less than propane, oil and resistance heat. Resistance heat costs three times as much as the COP 3 heat pump for the same warmth.

A heat pump moves heat from outdoor air into the house. ENERGY STAR notes that an air-source heat pump can deliver up to three times more heat than the electricity it uses. That ratio is the coefficient of performance, or COP.

Colder Air, Lower COP

As the outdoor air gets colder, the compressor must lift heat across a bigger temperature gap, so each kWh moves less heat. The outdoor coil can also frost up, and the unit spends energy on defrost cycles.

Backup Strips Run at COP 1

When the heat pump cannot keep up, many systems switch on electric resistance strips. Those strips turn each kWh into 3,412 Btu, a COP of exactly 1. The federal test for HSPF counts this backup energy in the seasonal total.

Use a Seasonal Average

That is why this calculator asks for a seasonal COP, not the best-case rating at mild temperatures. HSPF2 is rated for a moderate climate (Region IV), so homes in colder regions should expect a lower seasonal COP. Cold-climate models are tested down to 5 F for ENERGY STAR, which helps you compare them.

The defaults are the latest U.S. residential averages we found at EIA: electricity 18.31 cents per kWh (July 2026), natural gas $24.09 per thousand cubic feet (June 2026), and propane $2.674 and heating oil $5.535 per gallon (week of March 30, 2026, the last week of the 2025-26 heating season). We rounded them to $0.18 per kWh, $2.33 per therm, $2.67 and $5.54 per gallon. Prices vary a lot by state and by season, so type the prices from your own bills.

• Electricity: total bill divided by kWh used. For state averages, see the EIA Electric Power Monthly, Table 5.6.A, which lists residential prices in cents per kWh.
• Natural gas: use the price per therm on your bill. The EIA natural gas price page lists residential prices in dollars per thousand cubic feet (Mcf). At 1,036 Btu per cubic foot, 1 Mcf is about 10.36 therms, so divide by 10.36 to get dollars per therm.
• Propane and heating oil: the EIA Heating Oil and Propane Update publishes weekly residential prices per gallon during the heating season, October through March.

Fixed monthly charges do not change with use, so leave them out if you keep the service either way.

1. A home needs 60 MMBtu of heat a year. Power costs $0.18 per kWh and gas costs $2.33 per therm.
2. Gas furnace at 95% AFUE: 2.33 x 10 / 0.95 = $24.53 per MMBtu. Yearly: 60 x 24.53 = $1,472.
3. Heat pump at a seasonal COP of 3.0: 0.18 x 1,000,000 / 3,412 / 3 = $17.58 per MMBtu. Yearly: $1,055.
4. The heat pump is cheaper by about $416 a year.
5. Break-even COP: 52.75 / 24.53 = 2.151. Break-even power price at COP 3: 24.53 x 3 x 3,412 / 1,000,000 = $0.251 per kWh.
6. If the same home had an older 80% furnace, gas would cost $29.13 per MMBtu, or $1,748 a year, and the heat pump would save about $692.

Prices decide the answer. At $0.17 per kWh and $1.50 per therm, the example used in our companion article, gas costs $15.79 per MMBtu ($947 a year) and the heat pump $16.61 ($996), so the 95% furnace wins and the break-even COP rises to 3.16. Try the Article example chip, then your own numbers.

It depends on your prices and the heat pump's seasonal COP. At recent EIA U.S. averages of $0.18 per kWh and $2.33 per therm, a 95% gas furnace costs $24.53 per million Btu of heat and a COP 3 heat pump costs $17.58. On a 60 MMBtu load that is $1,472 versus $1,055 a year, so the heat pump saves about $416. At $0.17 per kWh and $1.50 per therm the answer flips: gas costs $947 and the heat pump $996.

It is the seasonal COP at which the heat pump and the furnace cost the same. Divide the cost of 1 MMBtu of electric resistance heat (COP 1) by the furnace cost per MMBtu. For $0.18 power and $2.33 gas at 95% AFUE, it is 52.75 / 24.53 = 2.151. If your seasonal COP is < 2.151, the gas furnace is cheaper to run.

HSPF2 is Btu of heat per watt-hour of electricity over a whole heating season. One watt-hour is 3.412 Btu, so seasonal COP = HSPF2 / 3.412. HSPF2 7.5, the federal minimum for new split-system heat pumps, is a COP of 2.198, and HSPF2 8.1 is 2.374. It is a seasonal average, not the COP on the coldest day.

Multiply last winter's fuel use by its heat content and by your old system's efficiency. For example, 700 therms x 100,000 Btu x 0.80 = 56.0 MMBtu delivered. Use 91,452 Btu per gallon for propane and 138,500 Btu per gallon for heating oil. Subtract fuel used for hot water and cooking first.

The colder the outdoor air, the harder the compressor must work to pull heat from it, and the unit also spends energy on defrost. On the coldest days, backup electric resistance strips may run at COP 1. The seasonal COP averages all of this, which is why it is lower than the rating at mild temperatures.

Usually, at typical prices. At $2.67 per gallon and 95% AFUE, propane heat costs $30.73 per MMBtu, and oil at $5.54 per gallon and 85% costs $47.06. A COP 3 heat pump at $0.18 per kWh costs $17.58. On a 60 MMBtu load it saves about $789 a year over propane and $1,768 over oil.

Break-even price per kWh = furnace cost per MMBtu x COP x 3,412 / 1,000,000. For gas at $2.33 per therm and 95% AFUE with a COP 3 heat pump, it is $0.251 per kWh. Below that, the heat pump wins. Use the full price on your bill, including delivery charges, divided by the kWh used.

• U.S. Energy Information Administration: British thermal units (Btu) (heat contents: 1 kWh = 3,412 Btu, 1 therm = 100,000 Btu, propane 91,452 Btu per gallon, heating oil 138,500 Btu per gallon, natural gas 1,036 Btu per cubic foot).
• eCFR: 10 CFR Part 430, Subpart B, Appendix M, test method for central air conditioners and heat pumps (HSPF is heat in Btu divided by electricity in watt-hours over the heating season, with backup resistance heat counted).
• eCFR: 10 CFR 430.32, energy conservation standards (heat pumps made on or after January 1, 2023: minimum HSPF2 of 7.5 for split systems and 6.7 for single-package units).
• ENERGY STAR: Air-Source Heat Pumps (up to three times more heat than the electricity used; cold-climate models tested down to 5 F; backup heat for colder days).
• EIA: Electric Power Monthly, Table 5.6.A, average price of electricity by state (default electricity price: U.S. residential 18.31 cents per kWh, July 2026).
• EIA: U.S. Natural Gas Prices (default gas price: U.S. residential $24.09 per thousand cubic feet, June 2026).
• EIA: Heating Oil and Propane Update (default propane $2.674 and heating oil $5.535 per gallon, U.S. residential, week of March 30, 2026).