Heat Pump Running Cost Calculator

Estimate what a heat pump costs to run in heating mode — kW draw, kWh used and dollars — from its capacity, COP and your own electricity rate.

Estimate: results come from the values you enter and standard reference constants. Get real written quotes and check your utility bill before you decide.
Refrigerant: Handling refrigerant requires EPA Section 608 certification — DIY charging is illegal and dangerous. This tool does not cover refrigerant work.

Calculator

BTU/h
The heating capacity at the outdoor temperature you care about — it drops as it gets colder.
COP
Heat delivered per unit of electricity. COP falls with outdoor temperature; use the value at your design condition.
h
Hours the compressor actually runs.
$/kWh
All-in $/kWh from your bill.
Cost to run$4.22
Power draw3.52 kW
Energy used28.14 kWh over 8.0 h
COP3.00

A 36,000 BTU/h heat pump at COP 3.00 draws 3.52 kW ≈ $4.22 for 8.0 h at $0.150/kWh.

A heat pump is a heat mover, not a heat maker: for every kilowatt-hour of electricity it draws, it delivers several kilowatt-hours of heat by pulling energy from the outdoor air. That multiplier is the COP (coefficient of performance), and it is the reason a heat pump can beat resistance heat and often gas. Running cost is just the electrical draw at that COP, priced at your own rate.

The catch is that COP is not constant — it falls as the outdoor temperature drops, because there is less heat to harvest and the compressor works harder. A cold-climate unit might see COP 3.5 at 47 °F and 2.0 near 5 °F. So enter the capacity and COP for the condition you actually care about (a mild evening, or a design-cold morning) rather than one number for the whole winter.

A heat pump also cools, and in cooling mode the same physics applies with the roles reversed — there the efficiency is quoted as EER or SEER2 rather than COP. For a straight cooling-cost estimate, use the AC running-cost tool with the unit’s EER; use this tool for heating, where the COP multiplier is what makes a heat pump attractive against resistance heat and, on the right rates, against gas.

Formula

The draw follows from the COP definition, converting heat output in BTU/h to electrical kW (1 kWh = 3,412 BTU):

  • kW = capacity (BTU/h) ÷ (COP × 3412)
  • kWh = kW × run hours
  • cost = kWh × your $/kWh rate

The 3,412 converts the BTU/h of heat into the electrical kilowatts consumed given the COP. If your spec sheet lists a seasonal HSPF2 instead of a COP, convert first (COP ≈ HSPF ÷ 3.412) or use the seasonal HSPF2 savings tool for whole-season energy.

Worked example

A heat pump delivering 36,000 BTU/h at COP 3:

  • kW = 36,000 ÷ (3 × 3,412) = 3.517 kW
  • One hour costs 3.517 kWh × $0.15 = $0.53
  • An 8-hour run costs 28.1 kWh × $0.15 ≈ $4.22

If a cold snap drops the COP to 2.0, the same 36,000 BTU/h now draws 5.28 kW and the hour costs about $0.79 — a 50% jump for the same heat. That temperature sensitivity is exactly why a balance point and, in cold climates, backup heat matter.

COP, temperature and the whole season

To compare a heat pump against burning fuel, don’t stop at the electric cost alone — put both on the same delivered $/MMBTU footing. The electric vs gas heat and $/MMBTU by fuel tools do that, and the heat pump vs gas furnace guide walks through when each wins.

For a whole-winter budget, a single COP is a rough proxy. Real seasonal performance blends many temperatures, which is what HSPF2 captures. Use this tool for a specific condition (“what does it cost per hour at 30 °F?”) and the HSPF2 tools for the seasonal total. Sizing still comes first: see heat-pump size.

Reference table

How a 36,000 BTU/h heat pump’s draw and hourly cost change with COP (at a sample $0.15/kWh):

COPPower drawCost per hour
4.0 (mild)2.64 kW$0.40
3.0 (typical)3.52 kW$0.53
2.5 (cool)4.22 kW$0.63
2.0 (cold)5.28 kW$0.79
1.5 (very cold)7.03 kW$1.06

Frequently asked questions

How much does it cost to run a heat pump?
A 36,000 BTU/h heat pump at COP 3 draws about 3.5 kW, so roughly $0.53 per hour at $0.15/kWh. The cost rises sharply as it gets colder and the COP falls, so budget with the COP at the temperatures you actually heat in.
What is a good COP for a heat pump?
At mild temperatures (around 47 °F) a modern heat pump often sees a COP of 3.5–4.5. Near freezing it may be 2–3, and in a hard freeze it can approach 1.5–2. A COP of 1 is the same efficiency as electric resistance heat.
COP or HSPF2 — which should I enter?
Enter a COP for a specific outdoor temperature. HSPF2 is a seasonal average across many temperatures; convert it with COP ≈ HSPF ÷ 3.412 if that is all you have, or use the HSPF2 seasonal tools for a whole-winter figure.
Why does the cost jump in cold weather?
Cold air holds less heat to harvest and the compressor must work harder, so the COP drops. Lower COP means more electricity for the same BTU of heat — the cost per hour can rise 50% or more between a mild evening and a design-cold morning.
Is a heat pump cheaper than gas?
It depends on your electricity rate, gas price, the COP and the furnace AFUE. Compare them head-to-head on delivered $/MMBTU with the electric-vs-gas tool rather than assuming — the answer flips with local prices.
Does this tool cover backup or auxiliary heat?
No — it models the heat pump’s own compressor draw at the COP you enter. When the outdoor temperature falls below the balance point, many systems bring on electric-resistance backup (effectively COP 1) or a gas furnace, which costs much more per BTU. To capture that, run the tool a second time at COP 1 for the backup share of the hours, or use the balance-point tool to find where the switchover happens.
What run hours should I use for a season?
Use realistic daily compressor hours for the temperatures you heat in, then multiply out by the number of days. Because the COP changes with weather, a whole-winter total is more accurate if you split it into a few temperature bands — mild, cold and design-cold — each with its own COP and hours, rather than one average.

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