Why might savings be negative?

If electricity is expensive vs gas or COP is low, heat pumps can cost more to run. Adjust rates/COP to your scenario.

Subtract incentives from heat pump cost to improve payback.

Hybrid/dual-fuel setups?

Not modeled; adjust hours to reflect heat pump vs furnace runtime.

Not included; this tool focuses on heating costs.

COP across temperatures?

Single average COP; real-world COP varies with outdoor temp.

finance calculator

Heat Pump vs Gas Heat Cost Calculator

Compare annual heating costs for a heat pump vs a gas furnace using load, runtime, COP/efficiency, fuel prices, and see payback on the heat pump premium.

Results

Annual gas therms: 1000.00
Annual gas cost: $1,250
Annual kWh (heat pump): 8242.97
Annual electric cost: $1,154
Annual savings (heat pump vs gas): $96
Simple payback (years): 41.67

How to use this calculator

Enter heating load (BTU/hr) and annual heating hours.
Enter heat pump COP and furnace AFUE, plus gas price and electric rate.
Enter installed costs for both systems.
Review annual gas vs electric costs, savings, and payback on the heat pump premium.

Inputs explained

Heating load: System capacity in BTU/hr.
Heating hours: Estimated annual runtime hours for heating.
Heat pump COP: Efficiency multiplier; higher COP = less kWh per BTU.
Furnace efficiency: AFUE as decimal (e.g., 0.9 = 90%).
Gas price per therm: Local gas price.
Electric rate: Your $/kWh rate.
Heat pump/furnace cost: Installed costs for each system.

How it works

Gas therms = (BTU/hr × hours × 1/100,000) ÷ furnace efficiency. Gas cost = therms × gas price.

Heat pump kW = (BTU/hr ÷ COP) ÷ 3,412. Electric cost = kW × hours × $/kWh.

Annual savings = gas cost − heat pump cost. Payback = (heat pump cost − furnace cost) ÷ savings.

Formula

Gas therms = (Load × Hours × 1/100,000) ÷ AFUE
Gas cost = Therms × Gas price
Heat pump kW = (Load ÷ COP) ÷ 3,412
Electric cost = kW × Hours × $/kWh
Savings = Gas cost − Electric cost
Payback = (Heat pump cost − Furnace cost) ÷ Savings

When to use it

Deciding between a new heat pump vs replacing/keeping a gas furnace.
Estimating payback on electrification when fuel prices differ.
Modeling savings with different COP or AFUE assumptions.

Tips & cautions

Use realistic COP at your winter temps; lab COP can be higher than field performance.
Gas and electric rates vary—rerun when prices change to keep payback accurate.
If you’ll keep the gas furnace as backup, adjust runtime to reflect actual usage split.
Cooling/shoulder-season savings not included; heating only.
COP varies with temperature; this is a single average COP.
Simple payback; no time value of money or incentives. Subtract rebates from heat pump cost to shorten payback.

Worked examples

60k BTU load, 1,500 hrs, COP 3.2, AFUE 90%, $1.25/therm, $0.14/kWh, HP $9,500, furnace $5,500

Gas therms ≈ 1,000; Gas cost ≈ $1,250
Heat pump kWh ≈ 28,074; Electric cost ≈ $3,930
Savings ≈ −$2,680 (more expensive if electricity > gas here); Payback not applicable

50k BTU load, 1,200 hrs, COP 4.0, AFUE 80%, $1.50/therm, $0.12/kWh, HP $10,000, furnace $6,000

Gas therms ≈ 750; Gas cost ≈ $1,125
Heat pump kWh ≈ 17,572; Electric cost ≈ $2,109
Savings ≈ −$984; Payback not favorable unless rates shift or incentives apply

Deep dive

This heat pump vs gas cost calculator compares annual heating costs using your load, runtime, COP/AFUE, and fuel prices, then shows simple payback on the heat pump’s higher upfront cost.

Use it to decide if electrifying heat makes financial sense at your energy rates and heating hours.

FAQs

Why might savings be negative?: If electricity is expensive vs gas or COP is low, heat pumps can cost more to run. Adjust rates/COP to your scenario.
Include incentives?: Subtract incentives from heat pump cost to improve payback.
Hybrid/dual-fuel setups?: Not modeled; adjust hours to reflect heat pump vs furnace runtime.
Cooling savings?: Not included; this tool focuses on heating costs.
COP across temperatures?: Single average COP; real-world COP varies with outdoor temp.

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