Furnace Replacement Cost Calculator

About the Furnace Replacement Calculator

A furnace replacement tends to arrive at the worst time — the first cold snap, when the old unit won't light. The final cost depends on the fuel you burn, how efficient the new furnace is, how big your home is, and whether the new unit drops into the old one's spot or needs new venting and gas work. This calculator combines the furnace, installation labor, high-efficiency venting when needed, old-unit disposal, and permits into a realistic low, average, and high range before you call for quotes.

How We Calculate Furnace Replacement Cost

We start with the furnace unit price for the fuel you choose, scaled gently by home size and — for combustion furnaces — by an efficiency multiplier for high-AFUE condensing models. On top of that we add installation labor (higher for gas, propane, and oil because of venting and fuel hookup), a high-efficiency venting and condensate line when applicable, a conversion line when you're switching fuel or relocating the unit, old-furnace disposal, and a permit. The result is split into materials and labor across low/average/high tiers.

Factors That Affect Furnace Replacement Cost

The biggest cost drivers are fuel type and efficiency. A standard 80% AFUE gas furnace is the value path; a 95%+ condensing model costs more for the unit and the PVC venting it requires. Oil furnaces cost the most; electric furnaces are cheap to install but expensive to run. After that come home size (which sets the BTU output), whether you're converting fuel or relocating the unit, the condition of your ductwork and chimney, and local labor rates — use the Location selector to adjust for your state. One thing to plan around: a federal efficiency rule is scheduled to raise the minimum to 95% AFUE for most new gas furnaces from 2028.

Furnace Cost by Fuel Type

Typical installed cost and operating profile by fuel. Installed cost is for a standard-efficiency, like-for-like replacement; high-efficiency and conversions run higher.

Source: Installed-cost ranges, 2026 (HomeAdvisor / Fixr); operating cost varies by local fuel and electricity prices.

80% vs. 95% AFUE: is high-efficiency worth it?

AFUE (Annual Fuel Utilization Efficiency) is the share of fuel a furnace turns into heat. An 80% furnace sends a fifth of your fuel dollars up the flue; a 95% condensing furnace wastes only a twentieth. The condensing model costs more — both the unit and the PVC venting and condensate drain it needs — but it claws that back through lower bills.

The payback math swings on climate and fuel price. In a cold northern climate with a long heating season and pricey gas, a high-efficiency furnace can pay for the upgrade in a handful of years and keep saving after. In a mild climate where the furnace runs a few weeks a year, the payback stretches out and a standard unit is often the smarter buy. One caveat that's tipping the scale: a federal Department of Energy rule is scheduled to raise the minimum to 95% AFUE for most new non-weatherized gas furnaces beginning in 2028, so high-efficiency is set to become the standard, not the upgrade.

Replace the furnace and AC together?

If your furnace and central AC are both near the end of their lives, replacing them as a matched system usually beats doing them piecemeal. The furnace houses the blower that also moves your cooled air, so a new high-efficiency furnace paired with an aging AC — or vice versa — leaves performance on the table. A matched, correctly sized system runs more efficiently and is easier to warranty.

There's a labor argument too: doing both at once means one mobilization, one set of permits, and one disruption instead of two, which typically trims the combined price. The flip side is the bigger bill all at once. If only one unit is failing and the other has real life left, replace the failed one now and plan for the other later — there's no rule that says they must die together.

Furnace Replacement Cost by Home Size

Natural gas furnace, standard 80% AFUE, like-for-like swap, at the national average. Use the calculator above for other fuels, high efficiency, and your state.

Sources

• • HomeAdvisor — Furnace Installation & Replacement Cost (2026)
• • Fixr.com — Furnace Replacement Cost
• • Angi — Cost to Replace a Furnace
• • U.S. Department of Energy — Furnaces and Boilers (Energy Saver) (checked 2026-06)

Costs are based on current industry ranges and vary by location and market conditions. See how we calculate costs — cost data last reviewed June 2026.