In Wisconsin, a high-efficiency gas furnace costs less to run than a heat pump, and electric baseboard costs the most of the three. That is a fuel-price comparison, though, and a missing gas line, an aging air conditioner or a hard cold snap can each change which system is the smarter buy.
The short answer for Wisconsin
The numbers come from a calculation built on U.S. Energy Information Administration (EIA) residential prices, ENERGY STAR efficiency levels and standard Btu conversions. Delivering one million Btu of heat to a house costs $10.68 with a natural gas furnace at 97% AFUE. A heat pump at 8.1 HSPF2 (a seasonal COP of about 2.4) costs $23.46. Electric resistance, such as baseboard heaters, costs $55.69.
Be clear about what these figures are. They are the running cost of the same amount of heat from each system, using statewide average prices. They are not a yearly bill, which depends on the size of the house, its insulation and your utility’s rate plan. They are also not the price of buying and installing equipment, which can easily change the long-term math.
So if a gas line already serves the house, the furnace wins on running cost by $12.78 per million Btu, and a heat pump has to win on something else. That “something else” might be cooling, a missing gas line or a replacement you have to make anyway. The sections below cover each one.
What each option costs to run in Wisconsin
| System | Efficiency used | Cost per million Btu delivered |
|---|---|---|
| Natural gas furnace | 97% AFUE | $10.68 |
| Heat pump | 8.1 HSPF2 (seasonal COP about 2.4) | $23.46 |
| Electric resistance (baseboard) | 100% efficient | $55.69 |
Electricity is the one price we can quote directly. EIA’s Electric Power Monthly (Table 5.6.B) puts the average Wisconsin residential rate at 19.00 cents per kWh, a year-to-date figure through July. It is a statewide average, so your utility and rate plan will differ. Use it to compare fuels, not to predict your bill.
The natural gas price behind the $10.68 also comes from EIA’s residential series. Gas rates are set utility by utility, so treat the furnace figure as a good estimate and confirm it against your own bill.
A fuel’s price per unit tells you little until you know how much heat each unit becomes. A baseboard heater turns every kilowatt-hour into one kilowatt-hour of heat. A heat pump moves heat rather than making it, so each kilowatt-hour yields more than that, which is why it lands at $23.46 on the same 19.00-cent power. A 97% furnace wastes only a sliver of the gas it burns, and gas is a cheap way to buy Btu in the first place. Cheap fuel and high efficiency stack together, which is why the furnace leads.
The heat pump figure uses the ENERGY STAR minimum for a ducted system, 8.1 HSPF2. ENERGY STAR asks 8.5 of a non-ducted (ductless) system for the same label, because it has no duct losses and has to be better to earn the badge. A ductless unit that just meets the bar would therefore cost somewhat less to run than the table shows. What HSPF2 Measures, and Why Ductless Asks for More explains the rating in detail. And since SEER2 measures cooling while HSPF2 measures heating, compare the same letter between units.
How cold it gets, and what that does to a heat pump
Milwaukee Mitchell Airport, the reference station here, averages about 6,450 heating degree days a year (base 65 F), according to NOAA’s 1991-2020 Climate Normals. A heating degree day adds up how far the day’s mean temperature sat below 65 F, so more of them means more fuel for the same house. Twice the degree days would mean roughly twice the fuel. Wisconsin’s winter is a long one, and that is one station: the northern part of the state runs colder.
The same normals put the average daily low of the coldest month at 17.2 F in Milwaukee. That is a mean, not a record. Individual nights go well below it, and those are the nights that test a heat pump.
The $23.46 above assumes a seasonal average. A heat pump’s efficiency falls as the outdoor air gets colder, so on the coldest nights it delivers less heat per kilowatt-hour than its seasonal rating suggests. That is why systems in cold states usually carry a backup: electric resistance strips inside the air handler, or a gas furnace that takes over when the heat pump can’t keep up. Resistance strips run at the $55.69 rate in the table, so a long stretch of deep cold pushes a heat pump house toward that figure for part of the day.
Our look at How Cold Is Too Cold for a Heat Pump goes through how modern cold-climate units handle that. A model built for cold weather narrows the gap, but the furnace still holds the running-cost lead in the table.
With about 6,450 heating degree days, assume the heat pump will need backup heat on the coldest nights, and ask any installer how that backup is sized and what it costs per hour to run.
What homes in Wisconsin already heat with
Heating equipment surveys tell you what was cheap when houses were built. According to the EIA’s Residential Energy Consumption Survey (RECS) 2020 state tables, 78% of Wisconsin homes heat mainly with a furnace and 8% with a steam or hot-water boiler. By fuel, natural gas heats 71% of homes, electricity 14% and propane 10%.
Two figures are missing. The survey does not publish a share for central heat pumps or for fuel oil or kerosene, because those estimates were suppressed as unreliable. That is not the same as zero. It means too few sampled households to report a number.
For most of the state, then, the usual swap is a furnace for a furnace, with the existing ductwork and gas line already in place. The heat pump becomes a bigger project there only if the ducts are poor. The 71% on gas also explains why the furnace leads the running-cost table: the infrastructure is already built, and gas is the cheap fuel.
The other houses matter for the opposite reason. A home on propane has no gas line, and this article has no propane price to compare, so get a delivered quote. For homes heated with electricity (the 14%), the survey does not say how many use baseboard versus other equipment. If yours uses baseboard, the table shows the stakes: $55.69 versus $23.46 per million Btu.
A boiler house is a different conversion. Radiators and baseboard hot water have no ducts, so a ducted heat pump has no air path to use. The usual options are a ductless system or a heat pump that makes hot water. Our article on Heating a Home in Wisconsin covers how those older systems are typically handled.
When the other choice wins
The furnace is cheaper to run, but running cost is only one line of the decision. The heat pump gets the nod in several situations.
The first is no gas service. Without a gas line, the real comparison is heat pump versus electric resistance or propane, and the heat pump’s $23.46 beats resistance at $55.69 by a wide margin. The second is cooling. Milwaukee averages about 780 cooling degree days a year, so summers are real, and a heat pump also cools. If your air conditioner is near the end of its life, one heat pump replaces both a furnace and an air conditioner, which changes the equipment math even though it doesn’t change the fuel math.
A third case is the dual-fuel setup, where a heat pump handles mild weather and keeps a gas furnace for the coldest days. It splits the difference: the furnace covers the nights when a heat pump is least efficient, and the heat pump takes the long shoulder seasons and the summer.
The fourth case runs the other way. An old system with years left may beat any replacement. If your furnace still works and its repair costs are modest, our piece on Repairing a Furnace or Replacing It helps you weigh that choice. And if you are leaning toward a heat pump but have no ducts, Ductless or Central compares the two layouts.
Choose the heat pump when you lack gas service or need to replace air conditioning anyway; choose the furnace when a working gas line is there and cooling is already handled.
Common questions
Is a heat pump cheaper than a gas furnace in Wisconsin?
Not on running cost. At average residential prices, the furnace delivers a million Btu for $10.68 and the heat pump for $23.46, per EIA prices and ENERGY STAR efficiencies. The heat pump can still come out ahead when it replaces air conditioning or when there is no gas line.
Is a heat pump cheaper than electric baseboard heat?
Yes. On the same electricity price, baseboard costs $55.69 per million Btu and a heat pump at 8.1 HSPF2 costs $23.46. The heat pump produces more heat per kilowatt-hour than a resistance heater.
Does a heat pump work in Wisconsin winters?
It works, but its efficiency drops in deep cold, and the 8.1 HSPF2 figure is a seasonal average. Milwaukee’s coldest-month average low is 17.2 F, and many Wisconsin systems pair the heat pump with resistance strips or a furnace for the coldest nights.
Do these figures tell me my yearly heating bill?
No. They compare the cost of the same amount of heat from each system at average statewide prices. Your bill depends on your house, your utility’s rates and how the system is set up, so use the figures for comparison and your own utility bills for planning.