Heat Pump Calculator
Compare a heat pump against a gas furnace using your real electricity and gas rates. Enter your rates, climate, and an estimated heating load to see annual heating cost for each option, the break-even gas price, and payback.
Use your local rates
Electric and gas prices swing wildly by state and utility. Your rates change the answer more than internet averages.
Climate-adjusted COP
Cold climates mean lower seasonal COP. We default to conservative ranges and let you override assumptions.
Model dual-fuel
If you want a furnace backup, set a heat-pump share and see how hybrid operation affects costs and payback.
What this heat pump calculator works out
You give the calculator five things: your electricity rate ($/kWh), your gas rate ($/therm), your climate, an estimated annual space-heating load in therms, and the seasonal efficiency you expect from the heat pump. From those, it converts your therms into an actual heat demand (using your current furnace's efficiency) and prices the same heat two ways.
You get the estimated annual heating cost for a gas furnace and for a heat pump side by side, the break-even gas price (the gas rate at which the two cost the same to run), and an optional simple payback once you add installed costs and incentives. You can also turn on a dual-fuel row to model a heat pump that covers most of the season with a furnace backup for the coldest days. If you have not estimated your heating load yet, run Bill Breakdown first and import the heating therms.
One honest caveat up front: this is a heating-only operating-cost comparison. It does not credit a heat pump for the summer cooling it provides, nor does it include fixed monthly utility charges. For the full decision, pair it with our guides on what a heat pump costs to run and installation cost.
Understanding the inputs
Each input below changes the answer in a specific way. The two that swing it hardest are your rates and the seasonal COP, so it is worth getting those right before you trust the payback number.
Electricity rate
This is what you pay per kilowatt-hour, found on your electric bill. A heat pump runs on electricity, so a higher rate raises its operating cost directly. Residential rates in 2026 commonly run from about $0.11/kWh in the lowest-cost regions to over $0.30/kWh in parts of the Northeast, California, and Hawaii.
Use the all-in rate, not just the supply charge: add the delivery and supply lines and divide by the kWh used. If you are on a time-of-use or tiered plan, use the blended rate that applies during the heating season, which is often higher than the headline rate.
Gas rate
This is what you pay per therm of natural gas, the fuel for the furnace side of the comparison. Like electricity, it varies widely: 2026 residential gas commonly lands between $0.80 and $2.50 per therm depending on your utility and the time of year, and winter rates often run above the annual average.
On a gas bill, combine the supply (commodity) and delivery charges and divide by therms used to get the true all-in rate. If you heat with propane or oil instead, convert that fuel to a cost-per-therm equivalent before entering it.
COP (coefficient of performance)
COP is the heat pump's efficiency: heat delivered divided by electricity consumed. A COP of 3.0 means three units of heat for every unit of electricity, which is why heat pumps can beat a furnace even where electricity looks expensive per unit of energy.
The number that drives your bill is the seasonal COP averaged across the whole heating season, not the rating at one mild temperature. Realistic seasonal values: roughly 2.1 to 2.9 in cold and very cold climates, 2.5 to 3.4 in mixed climates, and 2.7 to 3.6 in mild ones. Cold-climate units hold capacity better but still lose efficiency as it drops below freezing. Undersized equipment, leaky or undersized ducts, and high supply-water temperatures all push the real-world COP toward the bottom of the range.
The calculator's Conservative, Typical, and Optimistic scenarios set sensible COP defaults for each climate so you can see the spread instead of betting on a single optimistic figure. See how heat pumps perform in winter for the detail behind these ranges.
Climate
Your climate sets the default COP range and reflects how cold your worst heating hours get. In a cold climate the heat pump spends more hours at low outdoor temperatures, where its efficiency and output are lowest, so the seasonal COP and the case for a furnace backup both shift.
Pick the option that matches your design winter, not your average day. A mixed climate with a few hard cold snaps still benefits from a dual-fuel setup or a true cold-climate heat pump rated for low-temperature output.
Dual-fuel
A dual-fuel (hybrid) system runs the heat pump for most of the season and switches to a gas furnace on the coldest days, when the heat pump is least efficient and may not keep up. In the calculator you set the share of annual heating the heat pump covers; the rest is priced as gas, and you see the blended annual cost.
A typical heat-pump share for a well-set-up hybrid is 75 to 95 percent of annual heating. Lower it if you are in a very cold climate, run high supply temperatures, or prioritize comfort on the worst nights. Dual-fuel reduces risk and improves cold-weather comfort at the cost of shifting some heat back to gas. Our guide on dual-fuel heat pump and furnace systems covers when this setup makes sense.
Payback
Payback is the extra upfront cost of the heat pump, after incentives, divided by the annual heating savings. If a heat pump costs $7,000 more than a furnace after rebates and saves $500 a year on heating, the simple payback is about 14 years. Enter your installed costs and incentives to see it.
Treat it as a planning range. The estimate leaves out summer cooling savings, fixed charges, maintenance, financing, and future rate changes, all of which usually favor the heat pump in practice. Tighten it with two or three local quotes and the credits you actually qualify for, including the federal heat pump tax credit. When you are ready to plan the upgrade, our equipment starting point walks through next steps.
Frequently asked questions
Common questions about how the heat pump calculator works and how to read its results.
What does the heat pump calculator do?
It returns four outputs from five inputs: the annual heating cost of an air-source heat pump and a gas furnace side by side, the break-even gas price, and an optional simple payback. You enter your electricity rate ($/kWh), gas rate ($/therm), climate, an estimated annual heating load in therms, and the seasonal COP you expect. It converts your therms into actual heat demand using your furnace's efficiency, then prices that same heat both ways. Add installed costs and incentives for the payback, or turn on a dual-fuel row to model a furnace backup.
What is COP and what's a realistic value?
Realistic seasonal COP runs roughly 2.1 to 2.9 in cold climates, 2.5 to 3.4 in mixed climates, and 2.7 to 3.6 in mild ones, and these are the calculator's defaults per climate. COP (coefficient of performance) is units of heat delivered per unit of electricity drawn, so a COP of 3.0 means three units of heat per one of electricity. Use the seasonal average across the whole heating season, not the single-temperature lab rating. Undersized equipment, leaky or undersized ducts, and high supply-water temperatures push the real number toward the bottom of each range.
Why do my electricity and gas rates matter so much?
They move the answer more than any other input. Residential electricity runs from about $0.11/kWh in low-cost regions to over $0.30/kWh in parts of the Northeast, California, and Hawaii, while gas swings from roughly $0.80 to $2.50 per therm by utility and season. The comparison itself is electricity price divided by COP versus gas price per therm divided by furnace AFUE, so a 3x rate gap flips the winner. Two identical houses reach opposite conclusions purely on rates, which is why national-average comparisons rarely match your bill. Use the all-in rate printed on your statement, including delivery and supply lines, not internet averages.
What is the break-even gas price?
It's the gas price ($/therm) at which the heat pump and furnace cost exactly the same to run, derived from your electricity rate, assumed COP, and furnace AFUE. If your actual gas price sits above the break-even, the heat pump is cheaper to operate; below it, the furnace wins. Compare it to the gas rate on your bill for a one-number answer before reading the full cost breakdown.
How does dual-fuel work?
A dual-fuel (hybrid) system pairs a heat pump with a gas furnace; the heat pump carries 75 to 95 percent of annual heating in a well-set-up system, and the furnace takes the coldest days when the heat pump's efficiency and capacity drop. In the calculator you set the heat-pump share, the rest is priced as gas, and you see the blended annual cost. Lower the share in a very cold climate, with high supply temperatures, or when you prioritize comfort on the worst nights. It reduces cold-weather risk at the cost of shifting some heat back to gas.
How accurate is the payback estimate?
It's a simple estimate: the extra upfront cost of the heat pump after incentives divided by the annual heating savings, so $7,000 of extra cost saving $500 a year is about a 14-year payback. It ignores summer cooling savings, fixed utility charges, financing, maintenance, and future rate changes, all of which usually favor the heat pump, so treat the result as a planning range. Tighten it with real installed costs from two or three local quotes and the incentives you actually qualify for.
Does the calculator include cooling or fixed charges?
No, it's a heating-only operating-cost comparison. It excludes summer cooling savings (a heat pump replaces or supplements an AC), fixed monthly meter or connection charges, and comfort differences. Because a heat pump that also handles cooling lets you drop a separate AC, the real-world economics usually come out better than these heating-only numbers show.
Is the calculator free?
Yes, it's free with no sign-up. It runs entirely in your browser, so your rates and inputs stay on your device and nothing is sent to a server.