How the calculator works
The estimate starts from national installed-price ranges for each system type, then adjusts them in five steps:
- Equipment size. Cooling capacity is estimated from your square footage and climate zone (for example, about 575 sq ft per ton in a mixed climate). Furnace output is estimated in BTU per square foot and rounded up to the next common size.
- Efficiency. High-efficiency and variable-speed equipment raises the equipment share of the price by roughly 18% and 40%.
- Location. Each state has a cost index that reflects local labor rates. California and the Northeast run 15–25% above the national average; much of the South runs 5–10% below it.
- Installation access. Tight attics and crawlspaces add labor time.
- Ductwork and add-ons. These are listed as separate lines so you can compare them against the line items on a contractor's quote.
The typical figure sits a little below the midpoint of the range, because most installs use mid-tier brands and standard access.
Replacement cost by system type (2026)
National averages for a standard-efficiency install with existing ductwork, before state adjustment.
Central air conditioner
| Size | Capacity | Low | Typical | High |
|---|---|---|---|---|
| 1.5 ton | 18,000 BTU/h | $3,350 | $4,450 | $5,750 |
| 2 ton | 24,000 BTU/h | $3,800 | $5,000 | $6,500 |
| 2.5 ton | 30,000 BTU/h | $4,250 | $5,600 | $7,250 |
| 3 ton | 36,000 BTU/h | $4,700 | $6,200 | $8,000 |
| 3.5 ton | 42,000 BTU/h | $5,150 | $6,750 | $8,750 |
| 4 ton | 48,000 BTU/h | $5,600 | $7,350 | $9,500 |
| 5 ton | 60,000 BTU/h | $6,500 | $8,500 | $11,000 |
Heat pump (ducted, air-source)
| Size | Capacity | Low | Typical | High |
|---|---|---|---|---|
| 2 ton | 24,000 BTU/h | $4,700 | $6,400 | $8,500 |
| 3 ton | 36,000 BTU/h | $5,800 | $7,900 | $10,500 |
| 4 ton | 48,000 BTU/h | $6,900 | $9,400 | $12,500 |
| 5 ton | 60,000 BTU/h | $8,000 | $10,900 | $14,500 |
Cold-climate heat pumps, built to keep heating near full output below 5 °F, typically cost about 15% more. The calculator adds that premium automatically for cold and very cold zones.
Gas furnace
| Output | Low | Typical | High |
|---|---|---|---|
| 40,000 BTU | $2,500 | $3,350 | $4,400 |
| 60,000 BTU | $2,750 | $3,700 | $4,850 |
| 80,000 BTU | $3,000 | $4,050 | $5,300 |
| 100,000 BTU | $3,250 | $4,400 | $5,750 |
| 120,000 BTU | $3,500 | $4,700 | $6,200 |
Ductless mini split
| Indoor zones | Low | Typical | High |
|---|---|---|---|
| 1 zone | $2,500 | $3,400 | $4,500 |
| 2 zones | $4,000 | $5,600 | $7,500 |
| 3 zones | $5,500 | $7,750 | $10,500 |
| 4 zones | $7,000 | $9,900 | $13,500 |
| 5 zones | $8,500 | $12,100 | $16,500 |
Replacing a central AC and furnace together costs less than doing them separately, because the crew, the permit and much of the labor are shared. A 3-ton AC with an 80,000 BTU furnace typically runs $7,250 to $12,500.
What changes the price
- Efficiency rating. Moving from the 14.3 SEER2 minimum to an 18+ SEER2 variable-speed system can add $2,000–$5,000. It lowers electric bills, but payback is slow in mild climates.
- Ductwork condition. Leaky or undersized ducts waste 20–30% of conditioned air. Full replacement for a 2,000 sq ft home usually costs $3,500–$9,000.
- Electrical work. Heat pumps and larger AC units may need a new 240-volt circuit. Older 100-amp panels sometimes need an upgrade.
- Access. Attic installs in hot climates take longer and cost more than basement installs.
- Season. Spring and fall are the slow seasons for installers. Emergency replacements during a summer heat wave cost more and leave little time to compare quotes.
- Refrigerant. New systems use A2L refrigerants (R-454B or R-32). Old R-22 line sets are usually replaced rather than reused.
How HVAC size is chosen
Contractors size equipment with an ACCA Manual J load calculation, which accounts for insulation, windows, air leakage and orientation. This calculator uses a simpler square-foot rule by climate zone, which is fine for budgeting but not for choosing equipment.
| Climate zone | Sq ft per ton (cooling) | Heating BTU per sq ft |
|---|---|---|
| Hot · IECC 1–2 | 450 | 30 |
| Warm · IECC 3 | 525 | 35 |
| Mixed · IECC 4 | 575 | 40 |
| Cold · IECC 5 | 625 | 50 |
| Very cold · IECC 6–7 | 650 | 60 |
An oversized AC cools quickly but shuts off before removing humidity, leaving the house clammy. An undersized unit runs nonstop on the hottest days. If a quote is more than half a ton above or below this estimate, ask the contractor for their Manual J report.
Repair or replace?
A common rule of thumb is the $5,000 rule: multiply the age of the system in years by the repair cost. If the result is above $5,000, replacement usually makes more sense. A 12-year-old AC with a $450 repair gives 5,400, so replacing it is worth considering.
- Central AC and heat pumps usually last 12–17 years.
- Gas furnaces usually last 15–20 years.
- A failed compressor or cracked heat exchanger on an older system is usually a replacement, not a repair.
Ways to lower the cost
- Get at least three itemized quotes that list equipment model numbers, labor, permit and disposal separately.
- Schedule the replacement in spring or fall, before the old system fails.
- Check your state energy office and electric utility for heat pump and high-efficiency rebates.
- Replace the AC and furnace together if both are over 12 years old, to share labor costs.
- Have ducts sealed rather than replaced when they are structurally sound.
Frequently asked questions
How much does it cost to replace an HVAC system in 2026?
Most homeowners pay between $7,700 and $13,250 to replace a central AC and gas furnace together in a 2,000 sq ft home. A ducted heat pump of the same size usually costs $6,350 to $11,500. Prices are higher in California, the Northeast and Alaska.
How much does a new AC unit cost for a 2,000 sq ft house?
A 2,000 sq ft home in a mixed climate usually needs a 3.5-ton AC. Installed, that costs about $5,150 to $8,750 at standard efficiency, before ductwork or electrical work.
Is a heat pump cheaper than an AC and furnace?
A heat pump costs about the same as an AC and furnace replaced together, and less than the pair in mild climates. Operating costs depend on local electricity and gas prices. In very cold climates, a dual-fuel setup with a gas furnace backup is common.
Are there federal tax credits for a new HVAC system?
The federal Energy Efficient Home Improvement Credit (25C) ended for equipment installed after December 31, 2025. Many states and utilities still offer rebates for heat pumps and high-efficiency equipment, so check local programs before you buy.
How long does an HVAC replacement take?
A like-for-like AC or furnace swap usually takes one day. A full system with new ductwork takes two to four days.
Does the estimate include removing the old equipment?
Yes. Removal, disposal and refrigerant recovery are included in the system price, as they are in most contractor quotes.
These estimates are for budgeting only. Final prices depend on the equipment brand, your home's condition and local contractor rates. Cost ranges are compiled from published 2025–2026 national cost guides and adjusted with regional labor indexes.