Choose your state
Ranked by annual heating running-cost difference, on a 2,000 sq ft home.
Most heat pump calculators apply a single efficiency figure — often a COP of 3 or better — to every address in the country. That quietly assumes a mild winter everywhere. Real seasonal efficiency falls as it gets colder, because the unit works harder for each unit of heat and leans on resistance backup in cold snaps.
We derive efficiency from your state's heating degree days instead. The result is less flattering and considerably closer to what shows up on a bill: heat pumps win comfortably in mild climates with expensive gas, and lose in cold states where gas is cheap.
None of which means don't buy one. Rebates can be large, a heat pump replaces your air conditioner too, and gas prices move. It means go in with the real number.
Data vintage: Electricity: EIA Electric Power Monthly Table 5.6.B (residential, May 2026 YTD). Solar resource: PVGIS v5.3 (EU JRC), ERA5 2005-2023. Gasoline: AAA state averages. Natural gas: EIA residential by state. Heating degree days: NOAA CPC population-weighted normals. Retrieved 2026-08-03/04. Install costs, household usage, net-metering status, annual mileage, time-of-use spreads and outage hours remain estimates.