Free · Job cost estimators
Furnace Replacement Cost Estimator
Choose the fuel, size, efficiency and how much the install involves, and get a 2026 installed price range with the venting and relocation costs shown separately.
Install
Installed price range
$5,350 – $8,500
Midpoint
$6,900
typical quote
Spread
$3,150
low to high
Typical installed ranges and what drives them: Furnace Replacement Cost (2026) →
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What a furnace replacement costs
The furnace itself is $1,200–$4,000 wholesale depending on size, efficiency and staging; the installed price adds labor, plenum and transition sheet metal, venting, the gas connection, permit, removal and the contractor's margin. The estimator starts from a national installed range for the fuel and efficiency, adds about $350 per 20,000 BTU above 60,000, then adds venting or relocation work when the install is not a straight swap.
| Gas furnace, 80k BTU, straight swap | Installed range |
|---|---|
| 80% AFUE | $4,150 – $6,500 |
| 95–96% AFUE | $5,350 – $8,500 |
| 97%+ modulating | $7,350 – $11,500 |
| Electric furnace, 80k BTU | $2,850 – $5,000 |
| Oil furnace, 80k BTU | $6,350 – $10,500 |
80% or 95%?
An 80% furnace vents through the existing metal flue and costs the least to install. A condensing furnace (95%+) needs PVC intake and exhaust run to an outside wall and a condensate drain, which is the "new venting" line in the estimator, but it burns 15% less gas every winter and qualifies for many gas utility rebates. In a cold climate the payback is usually under seven years; in a warm one the 80% furnace often wins on total cost. If the old furnace shared a flue with a water heater, switching to condensing may orphan the water heater and require a liner, so check before quoting.
Size from the load, not the label
Furnaces have been oversized for decades. A house that had a 120k furnace installed in 1995 usually needs 80k today after windows, insulation and air sealing. Oversized furnaces short-cycle, run louder and wear out sooner. Run the load calculator and check the temperature rise with the CFM calculator at startup.
Frequently asked questions
How much does a new furnace cost installed in 2026?
For an 80,000 BTU straight swap in an average-cost region, a gas furnace runs about $4,150–$6,500 installed at 80% AFUE, $5,350–$8,500 at 95–96%, and $7,350–$11,500 for a 97%+ modulating unit. Electric furnaces are about $2,850–$5,000 and oil furnaces $6,350–$10,500. Smaller furnaces cost a little less.
How long does a furnace replacement take?
A straight swap is one day, usually 4–8 hours with two techs. Adding PVC venting for a condensing furnace or relocating the unit can push it to a day and a half.
What size furnace do I need?
Enough output to cover the heating load with a little margin. Output is input times AFUE, so a 100k input furnace at 96% delivers 96,000 BTU/h. A 2,000 sq ft house in a mixed climate needs about 90,000 BTU/h of output; a warm climate needs 60–70k and a cold one 110k or more.
Is a 96% furnace worth the extra cost?
In climates with real winters, yes: the fuel savings and utility rebates typically recover the $1,200–$2,000 difference in six to ten years, and the two-stage or modulating models are quieter and more comfortable. In the South the savings are small and an 80% furnace is often the better buy.
Should I replace the AC at the same time?
If the AC is more than 12 years old, usually yes. The indoor coil sits on top of the furnace and matched systems are cheaper to install together than separately, and a single visit means one permit and one crew day. The HVAC replacement estimator on this site prices the combination.