Furnace vs Heat Pump Calculator

Yes, if the unit is cold-climate rated — those hold rated capacity to around 5°F and are the default recommendation above roughly 0°F design temperatures. This model still derates them: in a cold-winter state (MN, ME, ND…), about 8% of delivered heat comes from 1-COP electric strips (vs 18% for a standard unit), dragging the effective seasonal COP to roughly 2.54 for the ≈10-HSPF2 tier. That is why the cold-climate row of the TCO table still favors cheap gas — but by a thinner margin than people assume.

Rule of thumb from this model: heat-pump heat reaches parity when your $/kWh is about 8% of your $/therm gas price — e.g. $1.40/therm gas ↔ 11.2¢/kWh, or $2.80/therm ↔ 22.4¢/kWh. Below that ratio the heat pump heats for less; above it, the furnace does. With the national-average pair ($1.40 and 17.3¢), gas still heats a bit cheaper per MMBtu, which is exactly what the annual-bill table shows.

No — a heat pump is an AC that can also run backwards. A ≈8.5-HSPF2 tier unit cools roughly like a same-tier SEER2 AC, which is why this calculator charges the furnace route for a new central AC whenever you actually need cooling, and why 'my AC just died' is the single most common moment people switch to a heat pump.

No for 2026 installations. The 25C Energy Efficient Home Improvement Credit (up to $2,000 for heat pumps, $600 for furnaces) applied only to equipment placed in service before December 31, 2025, per the IRS. Utility and state rebates still exist and can be worth $500–$2,000+ in some territories — subtract any real rebate you've confirmed from whichever option's equipment line before you decide.

Gas furnaces commonly run 15–30 years; air-source heat pumps typically 10–15, less where winters are harsh and strip use is heavy. This model assumes both serve the full 15 years. If your heat pump realistically dies at year 12 in a cold state, its true TCO rises by most of a second equipment+install — one more reason the furnace keeps winning cold-climate comparisons while mild-climate ones stay close.

Mostly yes. Set 'gas service' to 'new line' and the furnace route picks up roughly $1,800 for the service line and meter. And if you'd burn propane instead, the fuel arithmetic does the deciding: at the national propane average (≈$2.46/gal, EIA — the figure our water-heater calculators carry), propane delivers energy at about $27 per MMBtu versus about $14 for $1.40 gas — nearly 1.9× per unit of heat before any efficiency difference. Heating oil is similarly punishing. On delivered-heat dollars the heat pump wins almost every one of those comparisons, even before counting that an all-electric home needs no venting, no combustion air and no gas line to maintain. Running new gas service to an all-electric home rarely pays unless local gas is unusually cheap.

Duct condition (if the ducts need replacing, price it with the ductwork calculator — it hits both options), electrical-panel upgrades for heat-pump circuits, propane/oil fuel modeling, ground-source systems, ductless mini-splits (see the heat pump calculator), and any utility rebate you haven't confirmed. Install prices include permit, haul-away and startup but not structural or gas-pipe repairs beyond a new service line.

The model sizes both routes with the same rule of thumb: about 1 ton of cooling per 900 sq ft in a cold-winter state, 700 in a mixed climate, 550 where summers are long — so the 2,000 sq ft mixed-climate reference home lands near 2.9 tons, and the installed prices above scale with that size factor. Resist upsizing: an oversized furnace or heat pump short-cycles, wears parts faster and never runs long enough to dehumidify in summer. The honest sizing step is a Manual J load calculation from whoever installs — the square-foot rule is for ballparking budgets, which is exactly what this page is for, and the efficiency tier you pick moves the 15-year math more than the last half-ton.