Heat Pump vs Furnace Cost Calculator
Compare the annual heating cost of an electric heat pump against a gas furnace, using each fuel price and the heat pump’s seasonal efficiency (COP).
How it works
Heat pump kWh = MMBtu × 293.07 ÷ COP · Furnace therms = MMBtu ÷ AFUE ÷ 0.1 · Cost = usage × fuel price
A furnace can only deliver a fraction of the fuel it burns (its AFUE), so it always needs more energy input than the heat it produces. A heat pump moves heat rather than making it, so its COP is above 1 — a COP of 3 delivers three units of heat per unit of electricity. Whether the heat pump wins comes down to the ratio of electricity price to gas price versus the ratio of furnace-plus-losses to COP; cheap gas or a low winter COP can flip the answer.
Worked example
60 MMBtu of heat is 60 × 293.07 = 17,584 kWh. At a COP of 2.8 the heat pump draws 6,280 kWh, costing 6,280 × $0.17 = $1,068. A 92% furnace needs 60 ÷ 0.92 ÷ 0.1 = 652 therms, costing 652 × $1.40 = $913 — so here the gas furnace is cheaper by about $155.
Frequently asked questions
How do I find my heat pump’s COP?
Divide the unit’s HSPF rating by 3.412 for a rough seasonal COP, or use the manufacturer’s COP at your design temperature. Cold-climate models hold a COP near 2–3 well below freezing; older units drop toward 1.5–2 on the coldest days.
Does this include air conditioning?
No — this compares heating cost only. A heat pump also cools in summer, replacing a separate AC, which can tip the total economics further in its favor even when winter heating is a wash.
What about backup electric resistance heat?
On very cold days a heat pump may fall back to resistance heat at a COP of 1, raising its cost. This calculator uses a single seasonal COP, so lower it if your climate forces frequent backup-heat operation.
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This calculator is for educational purposes. Double-check important results before acting on them.