Furnace and AC Replacement Cost Calculator
Estimate the installed cost to replace your furnace and air conditioner together, based on your home size, the efficiency tier you choose, and whether new ductwork is needed.
What your result means
The estimated installed cost is a low-to-high range to replace the furnace and air conditioner together, scaled by your home size and the efficiency tier. The midpoint is a reasonable planning number. If you select new ductwork, that's added on top, since it's labor-heavy and priced by home size.
How to use this calculator
- Enter your home's conditioned square footage.
- Choose an efficiency tier — standard, high, or premium variable-speed.
- Indicate whether new or replacement ductwork is part of the job.
- Read the installed cost range and use the midpoint to budget.
- Get an in-home load calculation (Manual J) before buying — sizing matters.
The formula
A combined furnace-and-AC replacement scales roughly with home size and the equipment tier you pick. New ductwork is priced separately at about $1.50 a square foot because it's a major labor item.
Worked example
For a 2,000 sq ft home with a high-efficiency system and no new ductwork: 2,000 times $4.50 is $9,000. The range comes out to about $8,100 to $10,350, with a midpoint near $9,225. Adding ductwork at $1.50 a sq ft would tack on roughly $3,000.
Furnace and AC replacement cost factors
| Factor | Effect on price |
|---|---|
| Home size | Bigger homes need larger-capacity, costlier equipment |
| Standard efficiency | Lowest up-front cost (~80% AFUE / 14 SEER2) |
| High efficiency | Mid-tier; lower bills (~90%+ AFUE / 16+ SEER2) |
| Premium / variable-speed | Highest up-front; best comfort and efficiency |
| New ductwork | Adds roughly $1.50 per sq ft of home |
Tips & gotchas
- Replace both units together if either is near end of life — matched systems run more efficiently and you pay one install fee.
- Get a Manual J load calculation. Oversized equipment short-cycles and wastes money.
- Ask about rebates and tax credits — high-efficiency systems often qualify.
- This is an installed-cost estimate. Get itemized quotes that separate equipment, labor, and ductwork.
- Permit and disposal fees for the old equipment are sometimes extra.
Frequently asked questions
How much does it cost to replace a furnace and AC together?
For a typical home, a combined replacement runs about $7,000 to $12,000 installed. Larger homes, premium equipment, or new ductwork push it higher.
Is it cheaper to replace furnace and AC at the same time?
Often yes. You pay a single installation and get a properly matched system, which runs more efficiently than mismatched units replaced years apart.
Does home size affect the price?
Yes. Larger homes need higher-capacity equipment, so cost scales roughly with conditioned square footage.
What is a Manual J calculation?
An industry-standard load calculation that sizes equipment to your home. It prevents oversizing, which causes short-cycling and higher bills.
Does this include ductwork?
Only if you select it. New or replacement ductwork is a significant add, estimated here at about $1.50 per square foot of home.
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