HVAC Replacement Cost Calculator
Replacing a 3-ton AC + furnace system costs about $5,000–$11,000 installed, around $8,000 typical. With new ductwork it is $7,000–$16,000. A heat pump alone runs $3,800–$8,200.
Choose your system type, enter your home size to get a starting tonnage, pick an efficiency level and decide whether the ductwork is being replaced. The estimate splits equipment from installation labor so you can compare it with contractor bids.
Your system
Low end
$5,000
Typical
$8,000
High end
$11,000
Mid estimate: $2,000 labor · $6,000 materials & equipment
| Line item | Qty | Per unit (mid) | Range | Mid |
|---|---|---|---|---|
| AC + furnace (full system) — equipment3 ton, Standard (13–14 SEER) | — | — | $3,750 – $8,250 | $6,000 |
| Installation laborremoval, set, charge, startup | — | — | $1,250 – $2,750 | $2,000 |
| Total | $5,000 – $11,000 | $8,000 | ||
How this calculator prices your project
- Each system type starts from its published installed price range (typical = midpoint). AC, heat pump and AC + furnace ranges are scaled by tonnage relative to a 3-ton system, using the published installed cost per tonnage.
- Equipment is about 75% of an installed system (HomeGuide: $4,000–8,000 unit + $1,000–3,000 labor). Higher-efficiency options multiply the equipment share only, using the published price ratio of each SEER band to a standard 13–14 SEER unit.
- Ductwork replacement adds $2,000–$5,000; the labor/materials bar assumes half of that is labor (CostLoft assumption).
- Size suggestion uses a rule of thumb of roughly 1 ton per 600 sq ft. Climate, insulation and windows change this — a proper Manual J load calculation decides the real size.
- Choosing a state scales prices by that state's HVAC price level relative to the national average, from our state price data.
Price factors used
| Option | Published range | Multiplier | Basis |
|---|---|---|---|
| System · AC + furnace (full system) | $5,000–$11,000 | scaled by size | HomeGuide |
| System · Heat pump | $3,800–$8,200 | scaled by size | HomeGuide |
| System · Central AC only | $2,500–$7,500 | scaled by size | HomeGuide |
| System · Furnace only | $2,000–$5,400 | flat | HomeGuide |
| System · Ductless mini-split | $3,000–$10,000 | flat | HomeGuide |
| Size · 1.5 ton | $2,000–$5,000 | ×0.74 | ratio to 3-ton (HomeGuide AC installed cost) |
| Size · 2 ton | $2,500–$5,500 | ×0.84 | ratio to 3-ton (HomeGuide AC installed cost) |
| Size · 2.5 ton | $2,700–$6,000 | ×0.92 | ratio to 3-ton (HomeGuide AC installed cost) |
| Size · 3 ton | $3,000–$6,500 | ×1.00 | ratio to 3-ton (HomeGuide AC installed cost) |
| Size · 3.5 ton | $3,100–$7,000 | ×1.06 | ratio to 3-ton (HomeGuide AC installed cost) |
| Size · 4 ton | $3,500–$7,500 | ×1.16 | ratio to 3-ton (HomeGuide AC installed cost) |
| Size · 5 ton | $4,000–$8,000 | ×1.26 | ratio to 3-ton (HomeGuide AC installed cost) |
| Efficiency · Standard (13–14 SEER) | $1,000–$4,200 | ×1.00 | ratio of range midpoints (HomeGuide AC unit prices, applied to equipment only) |
| Efficiency · High (15–16 SEER) | $1,500–$5,700 | ×1.38 | ratio of range midpoints (HomeGuide AC unit prices, applied to equipment only) |
| Efficiency · High (17–18 SEER) | $1,800–$6,100 | ×1.52 | ratio of range midpoints (HomeGuide AC unit prices, applied to equipment only) |
| Efficiency · Very high (19–21 SEER) | $2,500–$7,500 | ×1.92 | ratio of range midpoints (HomeGuide AC unit prices, applied to equipment only) |
| Efficiency · Maximum (22–26 SEER) | $3,700–$8,500 | ×2.35 | ratio of range midpoints (HomeGuide AC unit prices, applied to equipment only) |
| Add-on · Ductwork replacement | $2,000–$5,000 | flat | HomeGuide |
| Sizing · ~1 ton per 600 sq ft | — | suggestion | CostLoft rule-of-thumb assumption; get a Manual J |
Sources
- HomeGuide — HVAC system cost by unit type, tonnage and SEER (2026) · retrieved 2026-11-05
Estimates are for planning purposes only. Actual prices vary by project details — always confirm with on-site quotes from licensed contractors.
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Frequently asked questions
How much does it cost to replace an HVAC system?
A full AC + furnace replacement for a typical home (3 ton) costs about $5,000–$11,000 installed. Adding new ductwork brings it to $7,000–$16,000.
How much does a new AC unit cost?
Central AC alone is about $2,500–$7,500 installed at 3 tons and $3,151–$9,451 at 5 tons in this calculator.
Is a heat pump cheaper than AC + furnace?
Usually, upfront: a heat pump runs about $3,800–$8,200 installed versus $5,000–$11,000 for an AC + furnace pair, because one unit does both heating and cooling. Running costs depend on your climate and energy prices.
How much more does a high-efficiency (high SEER) system cost?
A 19–21 SEER system raises a 3-ton AC + furnace replacement from about $8,000 to $13,520 typical in this calculator, because higher-efficiency equipment costs more while labor stays roughly the same.
What size HVAC system do I need?
A rough rule is about 1 ton of cooling per 500–600 sq ft, so a 1,800 sq ft home typically lands near 3 tons. Insulation, windows, climate and ceiling height all change this — ask your contractor for a Manual J load calculation instead of sizing by square footage alone.
How much does a ductless mini-split cost?
Ductless mini-split systems run about $3,000–$10,000 installed, depending mostly on how many indoor heads (zones) you need.