Heat Pump vs Furnace Calculator
Compare the annual heating cost of a heat pump and a gas furnace. Enter your heating demand and local prices. All prices are editable estimates.
How to calculate heat pump vs furnace cost
Heat pump: electricity needed = heating demand ÷ COP. Cost = electricity needed × electricity price.
Furnace: fuel needed = heating demand ÷ efficiency, then converted to therms. 1 therm = 29.307 kWh. Cost = therms × gas price.
Worked example (default values)
Heating demand 20,000 kWh, electricity $0.17 per kWh, gas $1.20 per therm, COP 3.0, furnace efficiency 80%.
Heat pump: 20,000 ÷ 3.0 = 6,666.67 kWh electricity, cost $1,133.33 per year.
Furnace: 20,000 ÷ 0.80 = 25,000 kWh fuel, which is 853.04 therms, cost $1,023.65 per year.
Result: in this example the furnace is cheaper by $109.69 per year. Change the prices to your local rates, because the cheaper option changes with local prices.
Second example (heat pump wins)
Same 20,000 kWh demand, electricity $0.12 per kWh, gas $1.50 per therm, COP 3.5, furnace efficiency 80%.
Heat pump cost $685.71 per year. Furnace cost $1,279.56 per year. Saving with a heat pump: $593.84 per year.
Tips
Use your last winter bill or your utility rates for the most useful result. COP falls in very cold weather, so a heat pump in a cold climate may not reach its rated COP all winter. Confirm equipment and installation costs with a local installer before you decide, because this calculator compares running cost only, not purchase or installation cost.
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Frequently asked questions
Is a heat pump always cheaper than a furnace?
No. It depends on your electricity price, gas price, heat pump COP and furnace efficiency. With the default values, the furnace is cheaper by about $110 per year.
What is COP?
COP is heat output divided by electricity input. A COP of 3.0 means 1 kWh of electricity gives 3 kWh of heat.
Are the prices accurate?
Prices are editable estimates. The defaults are typical US figures, and your local price can be higher or lower.
Does this include installation cost?
No. This calculator compares annual running cost only. Add installation cost separately if you want a payback time.