Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Heat pump annual cost
$942
Gas furnace annual cost
$913
Annual savings choosing the cheaper system
-$29
Cheaper to operate
Furnace
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How to use this
- 1Enter annual heating load (MMBtu).
- 2Enter furnace afue efficiency (%).
- 3Enter natural gas price ($/therm).
- 4Enter heat pump seasonal cop.
- 5Enter electricity price ($/kWh).
- 6Read your heat pump annual cost on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Compares annual operating cost between an electric heat pump and a gas furnace using your climate's heating demand (in heating degree days or a simplified annual heating-load input), each system's efficiency rating (COP/HSPF2 for heat pumps, AFUE for furnaces), and your local energy prices. Heat pumps move heat rather than generate it, so their effective efficiency (coefficient of performance) is typically 200-350% even after derating for cold-climate performance, while furnaces top out around 95-98% AFUE. The crossover point depends heavily on the price ratio between electricity and gas in your area, which is why heat pumps are a clear win in the Pacific Northwest but a closer call in a state with cheap gas and expensive electricity.
Worked example
Using the values the calculator loads with:
Inputs
- Annual heating load: 60 MMBtu
- Furnace AFUE efficiency: 92 %
- Natural gas price: 1.4 $/therm
- Heat pump seasonal COP: 2.8
- Electricity price: 0.15 $/kWh
Results
- Heat pump annual cost: $942
- Gas furnace annual cost: $913
- Annual savings choosing the cheaper system: -$29
- Cheaper to operate: Furnace
What each field means
Inputs
- Annual heating load (MMBtu)
- The annual heating load used in the calculation, measured in MMBtu. Starts at 60 MMBtu so you have a working example on load.
- Furnace AFUE efficiency (%)
- The furnace afue efficiency used in the calculation, measured in %. Starts at 92 % so you have a working example on load. Accepted range: 60–99 %.
- Natural gas price ($/therm)
- The natural gas price used in the calculation, measured in $/therm. Starts at 1.4 $/therm so you have a working example on load. Accepted range: 0.3–5 $/therm.
- Heat pump seasonal COP
- The heat pump seasonal cop used in the calculation. Starts at 2.8 so you have a working example on load. Accepted range: 1.5–4.5.
- Electricity price ($/kWh)
- The electricity price used in the calculation, measured in $/kWh. Starts at 0.15 $/kWh so you have a working example on load. Accepted range: 0.02–0.6 $/kWh.
Results
- Heat pump annual cost
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Gas furnace annual cost
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual savings choosing the cheaper system
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Cheaper to operate
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Where do I find my home's heating load?
Your gas bill's annual therm usage times roughly 100,000 Btu/therm gives a rough MMBtu total, or a Manual J load calculation from an HVAC contractor gives a precise design-day number you can scale to annual degree days. 40-80 MMBtu/year is typical for a mid-size US home depending on climate and insulation.
Why does COP drop in cold climates?
Standard heat pumps lose capacity and efficiency as outdoor temperature drops because there's less ambient heat to extract. Cold-climate heat pumps (using enhanced vapor injection compressors) maintain COP above 2 even at 5°F, while older or standard units may need electric-resistance backup heat below 20-25°F, which spikes the effective cost during a cold snap.
What COP number should I actually use?
Use the seasonal COP or HSPF2 rating divided by 3.412 to convert to COP, not the peak-condition COP on the spec sheet. A unit rated COP 4.0 at 47°F might average a seasonal COP of 2.5-3.0 across a full heating season in a mixed climate — using the peak number overstates savings.
Does this account for AC as a bonus with heat pumps?
No — this is heating cost only. A heat pump also provides cooling in summer, replacing a separate AC unit, which is a meaningful additional value not captured in a heating-only comparison and worth adding to your decision if you're currently paying for both a furnace and a separate AC system.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Simplified NEC-style load calc to check your panel capacity.
Insulation R-Value Upgrade Payback Calculator
Years to recoup the cost of adding attic or wall insulation.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Heat Pump vs Furnace Operating Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/heat-pump-vs-furnace
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/heat-pump-vs-furnace" target="_blank" rel="noopener">Heat Pump vs Furnace Operating Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Heat Pump vs Furnace Operating Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/heat-pump-vs-furnace) (2026).