Heat Pump vs Gas Furnace Calculator
Compare the annual operating cost of a heat pump against a gas furnace for the same heating load, using COP and AFUE efficiency ratings.
How this calculator works
Heating a home the same amount can cost very different amounts depending on whether you use a heat pump or a gas furnace, because the two systems convert energy into heat differently. A heat pump moves heat using electricity and its efficiency is measured by COP, while a gas furnace burns fuel and its efficiency is measured by AFUE.
This calculator takes the same annual heating load in BTU and runs it through both systems’ efficiency ratings and energy rates, so you can see the estimated yearly running cost of each side by side.
Formula: Heat pump: kWh used = annual BTU load ÷ (COP × 3,412). Cost = kWh × electricity rate. Gas furnace: therms used = annual BTU load ÷ (AFUE × 100,000). Cost = therms × gas rate per therm.
Worked example
- Annual heating load: 40,000,000 BTU
- Heat pump: COP 3.0, electricity at $0.15/kWh → cost ≈ $586.17/yr
- Gas furnace: AFUE 95%, gas at $1.20/therm → cost ≈ $505.26/yr
- In this example, the gas furnace is cheaper to run
Notes
Which system is cheaper flips with local electricity and gas rates and with the heat pump’s COP. A modern cold-climate heat pump with a high COP can beat gas even where electricity costs more per unit than gas, while a low-COP heat pump in a region with cheap gas usually loses. This comparison covers operating cost only — it doesn’t include equipment or installation cost for either system.
How to use
Enter your home’s annual heating load in BTU, then fill in the heat pump’s COP and your electricity rate, and the gas furnace’s AFUE and your gas rate per therm. The calculator returns the estimated annual running cost for each system so you can compare them directly for your own rates and equipment.
Operating-cost comparison only — it excludes equipment, installation, and maintenance cost. COP varies with outdoor temperature; confirm your specific equipment’s rated performance.
Frequently asked questions
What is COP and why does it matter for a heat pump's running cost?
COP, or coefficient of performance, measures how much heat a heat pump delivers compared to the electricity it consumes. A COP of 3.0 means it delivers 3 units of heat for every 1 unit of electrical energy used. A higher COP means the heat pump needs less electricity to produce the same amount of heat, directly lowering its operating cost.
What is AFUE and how does it affect a gas furnace's running cost?
AFUE, or annual fuel utilization efficiency, is the percentage of fuel energy a furnace actually converts into usable heat, with the rest lost as exhaust. A 95% AFUE furnace turns 95% of the gas it burns into heat for the home. A higher AFUE means less wasted fuel and a lower gas bill for the same heating load.
Is a heat pump always cheaper to run than a gas furnace?
No. Which one costs less depends on local electricity and gas prices along with the heat pump's COP. A modern, high-COP heat pump can beat gas even where electricity is pricier per unit than gas, while a low-COP heat pump in a region with cheap gas often loses. There's no universal answer — it depends on your local rates and equipment.
Does this calculator include the cost of buying and installing the equipment?
No, this comparison covers only the annual operating cost of running each system for the same heating load. It excludes equipment purchase price, installation, and maintenance costs, which can differ significantly between a heat pump and a gas furnace and should be factored in separately when deciding between the two.
Estimates only. Verify quantities with your supplier before purchasing.