Heat Pump vs Gas Furnace Cost Calculator
See what the same heat costs from a gas furnace and from a heat pump, at your state prices or your own.
The heat pump costs $487 more per year
- Gas furnace: $1,119 per year for 76 million Btu of heat.
- Heat pump: $1,606 per year, using 9,744 kWh. HSPF2 7.8 works out to a seasonal COP of 2.29.
- Break-even: both cost the same at an HSPF2 of 11.2, or at an electricity price of $0.115 per kWh.
Running energy only. HSPF2 is rated for one reference climate, so a heat pump in a colder place may use more electricity than this shows. Compare the break-even HSPF2 with the rating you expect in your climate.
This is an estimate, not a professional calculation. See the disclaimer and the methodology.
How it is calculated
The calculator asks how much gas you burn for heating in a year, in therms. A furnace turns only part of that gas into heat for the house, and the share is its AFUE. Heat delivered = therms × 100,000 Btu per therm × AFUE. Gas cost = therms × price per therm.
A heat pump has to supply the same heat with electricity. HSPF2 is the heat it supplies in Btu for each watt-hour of electricity over a heating season. Electricity = heat delivered ÷ HSPF2 ÷ 1,000 kWh. Electricity cost = kWh × price per kWh.
Dividing HSPF2 by 3.412 (the Btu in one watt-hour) gives the seasonal COP, the number of units of heat per unit of electricity. HSPF2 7.8 is a COP of 2.29. That conversion is our arithmetic on EIA's factor of 3,412 Btu per kWh. No official page we read states it.
The state prices are 2024 annual averages from the U.S. Energy Information Administration (EIA): residential natural gas in dollars per thousand cubic feet, turned into dollars per therm at 1,037 Btu per cubic foot (the 2024 U.S. average heat content), and the average residential electricity price. Both are revenue divided by volume, so they include the fixed charges that utilities spread over each unit. Your own marginal rates may differ.
The result is running energy only. It leaves out installation, maintenance, equipment life, rebates, defrost cycles, backup heat and any change in your cooling use. The break-even lines show the HSPF2, or the electricity price, at which the two systems cost the same, so you can test the result against the efficiency you expect in your climate.
Worked examples
The same home at U.S. average prices (2024)
800 therms a year, a 95 percent AFUE furnace (the ENERGY STAR minimum for the South) and a 7.8 HSPF2 heat pump (the ENERGY STAR minimum for split systems). Gas at $1.40 per therm costs $1,119. The heat pump uses 9,744 kWh at 16.5 cents, $1,606. The heat pump costs $487 more to run.
An older 80 percent furnace
To deliver the same 76 million Btu, an 80 percent AFUE furnace burns 950 therms instead of 800. At the same U.S. prices that gas costs $1,328 a year. The heat pump uses the same 9,744 kWh and costs the same $1,606, so it comes out $277 more to run than the old furnace. Always enter the therms you really burn, because the calculator works out the heat from them.
The same equipment in two states
With 800 therms, 95 percent AFUE and 7.8 HSPF2, Idaho prices ($0.82 per therm, 11.5 cents per kWh) make the heat pump $466 more to run. Massachusetts prices ($2.11 per therm, 29.4 cents per kWh) make it $1,170 more. The gap depends on both prices at once, so start from your state and then use the rates on your own bills.
Frequently asked questions
Is a heat pump cheaper to run than a gas furnace?
It depends on the price of gas, the price of electricity and the efficiency of both machines. The calculator compares them for your numbers. The break-even lines show how efficient the heat pump has to be, or how cheap electricity has to be, for the two to cost the same.
What is AFUE?
ENERGY STAR describes AFUE as, in general, the percentage of the heat in the incoming fuel that is converted to space heat instead of being lost. A 95 AFUE furnace sends about 95 percent of the gas energy into the house. ENERGY STAR certifies gas furnaces at 95 percent AFUE or greater in the South and 97 percent or greater in the North.
What is HSPF2?
HSPF2 is the heat a heat pump delivers over a heating season, in Btu, divided by the electricity it uses, in watt-hours. ENERGY STAR defines it for one reference climate (region IV). The ENERGY STAR minimum is 7.8 for split systems and 7.2 for single package units.
Will a heat pump work in cold weather?
ENERGY STAR says its certified air-source heat pumps are tested for low-temperature performance down to 5°F, and that a cold climate heat pump keeps working below that but is most efficient when paired with a back-up heat source at even lower temperatures. Its cold climate tier asks for an HSPF2 of 8.1 or more for ducted split systems and 8.5 for non-ducted ones. This calculator uses one HSPF2 for the whole season. If you expect your climate to cost you efficiency, enter a lower number.
How do I find my therms of gas for heating?
Your gas bill shows the gas used each month, often in therms or in ccf (100 cubic feet). Take the use in the heating months and subtract the use in months you do not heat, which covers cooking and water heating. If the bill is in ccf, use the therm factor printed on the bill. With the U.S. average heat content of 1,037 Btu per cubic foot, one ccf is about 1.04 therms.
Why does the calculator use 2024 prices?
They are the latest full year where EIA reports a residential gas price for every state and the District of Columbia. The 2025 column has gaps for six states. A single summer month would not describe the cost of heating, because utilities spread fixed charges over very little gas in summer.
Does the result include installation, rebates or maintenance?
No. It compares the energy to run the two systems. Equipment and installation prices, tax credits, rebates and maintenance are different for every home and are not included.
Related calculators
Sources and last update
- U.S. Energy Information Administration, Natural Gas Prices: Average Residential Price (annual, 2024)
- U.S. Energy Information Administration, heat content of natural gas delivered to consumers (U.S., annual)
- U.S. Energy Information Administration, 2024 Average Monthly Bill, Residential (average price by state)
- U.S. Energy Information Administration, Btu conversion factors (kWh and therm)
- ENERGY STAR, Air Source Heat Pumps key product criteria (HSPF2, cold climate)
- ENERGY STAR, Furnaces key product criteria (AFUE)
- U.S. Energy Information Administration, copyrights and reuse
Last updated: November 3, 2026. See methodology and sources.