Furnace Replacement Cost Estimator
Enter your home size and efficiency tier for installed furnace pricing.
Runs entirely in your browser — your numbers never leave this page.
How it works
Furnace = right-sized unit + efficiency tier:
- Sizing (~35 BTU/sq ft): a 2,000 sq ft home needs ~70k BTU. Oversized furnaces short-cycle and die young.
- 80% AFUE (~$3,800): standard — 20 cents of every fuel dollar goes up the flue.
- 92% (~$5,200): sealed combustion, PVC venting — the value sweet spot.
- 96%+ (~$6,800): condensing — maximum savings, needs a drain for condensate.
- Payback: the 92% vs 80% gap pays back in ~5–8 years through fuel savings.
- Replace at 15–20 years: even working furnaces that old waste enough fuel to justify replacement.
Frequently asked questions
How much does furnace replacement cost?
About $3,800 (80%), $5,200 (92%), $6,800 (96%+) installed for a typical home — oil/propane add a bit.
What size furnace do I need?
Roughly 35 BTU per sq ft — 70k BTU for 2,000 sq ft. A Manual J calculation is the precise method.
Is high-efficiency worth it?
Yes — the 92% vs 80% premium pays back in ~5–8 years via fuel savings, then saves every year after.
How long do furnaces last?
15–20 years. Replace proactively — ancient furnaces waste 20–40% of fuel.
What is AFUE?
Annual Fuel Utilization Efficiency — % of fuel converted to heat. 80% wastes 20%; 96% wastes 4%.
Gas vs oil furnace?
Gas: cheaper to run and install. Oil: common where gas isn't available; conversion to gas costs $2k–5k but pays off.
Should I replace AC at the same time?
Often yes — matched systems share the air handler; combined install saves ~$1,000–2,000 vs separate visits.
What about heat pumps?
Cold-climate heat pumps now rival furnaces in many regions, with tax credits — worth quoting alongside.
Are there tax credits?
High-efficiency furnaces and heat pumps often qualify for federal credits — check current rules before buying.
Why is my old furnace so expensive to run?
A 25-year-old 65% furnace burns ~50% more fuel than a modern 96% unit for the same heat.