Heat pump versus furnace operating cost

A heating comparison starts with the heat delivered to the house, in Btu, and then applies a price and an efficiency to each fuel. The prices are the residential electricity, natural gas, and propane prices EIA publishes. The efficiency is yours to set, because the comparison is about the equipment you are looking at. This guide uses the factors printed on EIA's conversion pages as checked October 10, 2026, the 2025 EIA-861 state electricity prices, the 2025 annual residential gas price, and the residential propane price for the week of October 5, 2026.

The conversion factors

EIA's standard conversion is 3,412 Btu per kilowatt-hour. Electric resistance heat converts each kilowatt-hour into 3,412 Btu of heat. A heat pump is rated with HSPF2, seasonal Btu of heat per watt-hour. Because a kilowatt-hour is 1,000 watt-hours, kilowatt-hours equal delivered Btu divided by HSPF2 times 1,000. An HSPF2 of 8 means 8 Btu per watt-hour, or 8,000 Btu per kilowatt-hour, which is more heat per kilowatt-hour than resistance. The 8 is the starting value in the calculator. Set it to the HSPF2 on the unit you are comparing.

Furnace efficiency is AFUE, output divided by input. An AFUE of 0.95 means 95 percent of the fuel's heat content becomes delivered heat, so the fuel you buy is the delivered Btu divided by 0.95. EIA's 2026 consumer-average heat content for natural gas delivered to customers is 1,036 Btu per cubic foot. One thousand cubic feet, an Mcf, is 1,036,000 Btu, or 10.36 therms, because a therm is 100,000 Btu. Propane on EIA's sample Btu table is 91,452 Btu per gallon. The heating tool uses 3,412, 1,036, and 91,452. Gasoline, at 120,166 Btu per gallon on the conversion calculator, belongs to the EV comparison, not to a furnace.

A worked example at 10 million Btu

Take 10,000,000 Btu of delivered heat. That number is the default so the arithmetic has a starting point. Change it to an audit, a design load, or a figure you derived from last winter's bills. Resistance kilowatt-hours are 10,000,000 divided by 3,412, which is 2,930.8 kilowatt-hours. A heat pump at HSPF2 8 uses 10,000,000 divided by 8,000, which is 1,250 kilowatt-hours. A 95 percent furnace needs 10,000,000 divided by 0.95, which is 10,526,316 Btu of fuel input, or 105.26 therms.

Price the electricity at Texas's 2025 residential all-in average of 15.40¢ per kilowatt-hour, from the EIA-861 Average Bill file. Resistance is 2,930.8 times 15.40¢, about $451.34 before the final cent rounding the tool applies to the unrounded product. The heat pump is 1,250 times 15.40¢, which is $192.50. The ratio follows the kilowatt-hours: 2,930.8 divided by 1,250 is 2.345, and $451 divided by $192.50 is the same ratio. At a higher HSPF2 the heat-pump kilowatt-hours fall. At a lower one they rise. The tool recalculates from the HSPF2 you type.

Natural gas in Texas in the 2025 annual residential series is $19.42 per Mcf. The series is stamped June 30, 2025, and the workbook's contents sheet describes 2025 as the latest year, released September 30, 2026. Input of 10,526,316 Btu divided by 1,036,000 Btu per Mcf is 10.160 Mcf. At $19.42 that is about $197.31. The U.S. residential gas price in the same file is $15.34 per Mcf. California is $22.01. The Texas electric comparison and the Texas gas price belong together when the house is in Texas. The tool switches both prices when you switch the state.

Propane for the week of October 5, 2026, is $3.101 per gallon in Texas and $2.598 in the United States. Gallons are 10,526,316 divided by 91,452, which is 115.10 gallons. At the Texas price that is about $356.93. At the U.S. price it is about $299.04. Propane and natural gas come from different series in these files: propane is a weekly heating-season price, gas is an annual price. The tool prints both dates.

States that use the U.S. fuel price

The 2025 annual residential gas workbook has 44 states. Connecticut, Maryland, Maine, North Carolina, Rhode Island, South Carolina, and West Virginia use the U.S. price of $15.34 per Mcf, and the tool says the price is national. The propane file for the week of October 5, 2026, publishes a subset of states. A state outside that subset uses $2.598 and is labeled national. Electricity is present for all 51 Average Bill rows, so the electric side of the comparison stays on the state price even when the fuel side uses the U.S. price.

Hawaii's residential gas price in the annual file is $52.38 per Mcf, so the tool uses the Hawaii cell rather than the U.S. average. Hawaii's electricity price in the 2025 Average Bill file is 40.40¢. A heat pump and a gas furnace in Hawaii are priced with those two Hawaii figures when the state selector is on Hawaii.

What the four totals cover

The four totals are the cost of energy for the same delivered Btu, at the efficiencies you enter and the EIA prices for the state you select. Equipment, ductwork, a service panel, a gas line, a propane tank rental, and a thermostat are capital costs, and they belong in a separate column from the fuel. The residential averages used here are energy revenue over energy sales. HSPF2 is already a seasonal rating. If you have a colder-climate performance number, type that number.

Ten million Btu is the starting load in the box. If you have a load from an energy audit, use that. If you have last winter's gas therms, convert therms to delivered Btu by multiplying by 100,000 and by the furnace AFUE, and then run the heat pump on the delivered heat. That conversion uses your bill.

Electric resistance at 3,412 Btu per kilowatt-hour is the higher kilowatt-hour path for a given load, among the electric options in the tool. A heat pump with HSPF2 above 3.412 uses fewer kilowatt-hours than resistance for the same delivered Btu. HSPF2 ratings in the federal test procedure sit above that, which is why the heat-pump result is lower. The exact gap is the HSPF2 in the box.

How to read the four totals

Read them as the cost of the same delivered Btu at the stated efficiencies and the stated EIA prices. Change the state before you compare a house in another state. Change HSPF2 and AFUE to the equipment you have in mind. The electricity year is 2025. The gas year is 2025. The propane week is October 5, 2026. Those stamps are on the result. A fuel rider your gas utility added after the annual average was compiled sits outside the $19.42 Texas figure, just as a 2026 electric rider sits outside the 15.40¢ Texas electricity figure. For a current electric schedule, use the bill calculator where a sheet was checked. The heating tool stays with EIA for the fuel prices. On the 10 million Btu example in Texas, resistance, the heat pump at HSPF2 8, natural gas, and propane land in that order from the factors above: about $451, $192.50, $197, and $357. Those dollars move when the state, the load, or the efficiency changes. The order is the point of running the four side by side on one load.