Heat pump vs furnace calculator
If you heat with electric resistance now, this is the heating share of your winter kWh.
The 15,000 kWh shown is an example.
Use the price from your bill if you know it.
Seasonal heat out per unit of power in. 2.5 is an example.
Printed on the furnace.
Use your bill. 1.40 is an example.
Yearly heating cost
Lowest running cost with these inputs: gas furnace.
Running cost only. It leaves out equipment, installation, rebates and any difference in air conditioning. A heat pump's real efficiency falls in very cold weather, so use a seasonal figure for your climate.
How the three costs are worked out
- Electric resistance. One kWh of electricity gives one kWh of heat. Cost equals heat needed times your price per kWh.
- Heat pump. It moves heat, so one kWh of electricity gives COP kWh of heat. Cost equals heat needed divided by COP, times your price per kWh.
- Gas furnace. One therm holds 29.3 kWh of heat. The furnace delivers that times its AFUE. Therms burned equal heat needed divided by that, and cost equals therms times your gas price.
COP, short for coefficient of performance, is heat delivered divided by electricity used. AFUE is the share of the gas that becomes heat in the home.
A worked example
| System | Energy used | Cost per year |
|---|---|---|
| Electric furnace or baseboard | 15,000 kWh | $2,585 |
| Heat pump, COP 2.5 | 6,000 kWh | $1,034 |
| Gas furnace, 95% AFUE, $1.40 a therm | 539 therms | $754 |
Source: Electricity: 17.23 cents per kWh, the 2025 US residential average from EIA Form EIA-861. The 15,000 kWh of heat, the COP of 2.5 and the gas price are examples.
The heat pump uses 60 percent less electricity than the resistance furnace for the same heat, so it costs $1,551 a year less in this example. Against gas, the answer turns on the two fuel prices.
The gas price where the two tie
At the US average electricity price, a COP of 2.5 and a 95 percent furnace, gas and the heat pump cost the same when gas is about $1.92 a therm. If your gas costs less, the furnace is cheaper to run. If it costs more, the heat pump is. Electric resistance heat ties with that furnace at about $4.80 a therm. Check your own gas bill for the real price, and use your own electricity price, because both vary by state.
Why the COP is not one number
A heat pump delivers more heat per kWh when the outside air is mild and less when it is very cold. The seasonal COP you enter should reflect your climate. Equipment ratings, a local installer or a utility rebate page can give a realistic figure. Very cold spells may also trigger electric backup heat, which has a COP of 1, and that raises the real cost above the calculator's estimate.
What the calculator leaves out
- The cost of buying and installing each system, and any rebates.
- Cooling. A heat pump also cools, and that may let you drop a separate air conditioner.
- Maintenance, fan electricity for a gas furnace and the fixed monthly gas charge.
- Changes in energy prices over the life of the equipment.
Frequently asked questions
Is a heat pump cheaper to run than a gas furnace?
It depends on your electricity price, your gas price and the heat pump’s seasonal efficiency. Where gas is cheap and electricity is expensive, the furnace usually costs less to run. Where electricity is cheap or gas is costly, the heat pump often does. The calculator tests your own prices.
What COP should I use?
Use a seasonal figure for your climate, from the equipment ratings or an installer’s estimate. 2.5 is an example only. Colder climates tend to have lower seasonal figures than mild ones.
How do I find the heat my home needs?
If you heat with gas, multiply your yearly therms by 29.3 and by the furnace efficiency, which the calculator does when you choose the gas option. If you heat with electric resistance, use the kWh your heating used last winter.
Does this include rebates and installation costs?
No. It compares running costs only. Add the purchase price, installation and any rebates to judge the full cost over the life of the equipment.