Replacing an HVAC system costs $5,000 to $11,000 including a new furnace and AC unit, or $7,000 to $16,000 with new ductwork.2 Angi’s average replacement lands at $7,500, reaching $22,000 with new ducts and add-ons.1 Budget $3 to $6 per square foot of home.2 Prices below are national averages* for 2026.
*National averages, not local quotes. Your price depends on system type and size (tons/BTUs), efficiency rating, ductwork condition, climate zone, and local labor rates.
$7,500
average replacement, Angi
$3 – $6
per sq ft, HomeGuide
$1,000 – $3,000
typical labor, HomeGuide
3 – 5 days
install time with ductwork, HomeGuide
Quick math: HomeGuide’s $3-to-$6-per-square-foot rule prices a 2,000 sq ft house at $6,000 to $12,000 — the same figure its size table publishes.2 Labor is $1,000 to $3,000 of that, roughly a quarter of an average job.2
Cost by system type
| System | Angi | HomeGuide |
|---|---|---|
| Central air conditioner | $3,900 – $7,900 | $2,500 – $7,500 |
| Gas furnace | $3,800 – $10,000 | $2,000 – $5,400 (any furnace) |
| Electric furnace | $1,700 – $7,100 | — |
| Heat pump | $4,200 – $7,600 | $3,800 – $8,200 |
| Ductless mini-split | $2,000 – $14,500 | $3,000 – $10,000 |
| Boiler | $3,700 – $8,300 | $2,200 – $10,000 |
| Geothermal heat pump | $4,500 – $24,500 | $15,000 – $35,000 |
The wide geothermal disagreement is real: Angi’s range starts at $4,500 where HomeGuide starts at $15,000.12 Geothermal quotes vary enormously with loop type and yard work, so treat both as “get three local quotes” territory rather than a budget number.
Cost by size (tons and BTUs)
Cooling capacity is measured in tons; heating in BTUs. HomeGuide’s installed-price table by AC size:2
| AC size | BTU | Unit price | Installed |
|---|---|---|---|
| 1.5 tons | 18,000 | $1,000 – $3,800 | $2,000 – $5,000 |
| 2 tons | 24,000 | $1,200 – $4,000 | $2,500 – $5,500 |
| 2.5 tons | 30,000 | $1,500 – $4,500 | $2,700 – $6,000 |
| 3 tons | 36,000 | $1,700 – $5,000 | $3,000 – $6,500 |
| 4 tons | 48,000 | $2,000 – $5,500 | $3,500 – $7,500 |
| 5 tons | 60,000 | $2,500 – $6,000 | $4,000 – $8,000 |
Angi’s sizing guide maps 1.5 tons to 600–1,000 sq ft, 3 tons to 1,600–2,000 sq ft and 3.5 tons to 2,000–2,500 sq ft, but stresses there is no strict per-square-foot rule: climate zone, insulation, windows and home age all shift the sizing.1
Ductwork and add-ons
| Item | Average cost | Source |
|---|---|---|
| Ductwork replacement | $1,400 – $5,600 | HomeGuide2 |
| New ductwork (no existing ducts) | $2,400 – $6,600 | HomeGuide2 |
| Ductwork (Angi’s average job) | ~$3,500 ($1 – $13 per linear ft) | Angi1 |
| Permits | $100 – $250 replacement; $250 – $1,500 with ducts | HomeGuide2 |
| New thermostat | $120 – $260 | Angi1 |
| Asbestos removal (pre-1986 homes) | $5 – $15 per sq ft | HomeGuide2 |
Ducts last 10 to 20 years, so they often need work in the same visit as a system older than 15 years.2 Note Fixr’s central-AC average of $8,750 already includes new ductwork — the main reason it sits above Angi’s $3,900 to $7,900 and HomeGuide’s $2,500 to $7,500 for the AC alone.123
Why 2023–2026 quotes run higher than older ones
SEER2 efficiency rules that took effect January 1, 2023 raised minimum efficiency on all new ACs and heat pumps, and Fixr estimates the change pushed system prices up roughly 15% to 20%.3 If a neighbor quotes what they paid in 2021, expect today’s number to be higher.
Worked examples
Example 1 — 2,000 sq ft house, furnace + AC replacement. HomeGuide’s per-square-foot rule: 2,000 × $3 to $6 = $6,000 to $12,000, matching its published figure for that size.2 Angi’s $7,500 average sits inside the band.1
Example 2 — 3-ton central AC swap, existing ducts. HomeGuide: $3,000 to $6,500 installed.2 Angi’s central-air range is $3,900 to $7,9001 — the $3,900 to $6,500 overlap is the well-supported band. Fixr’s low-end change-out of the same 3-ton unit is $3,750, just below it.3
Example 3 — full job with new ducts. HomeGuide’s $7,000 to $16,000 with ductwork2 reconciles with Angi’s calculator: a $3,900–$7,900 central air system plus ~$1,500 labor, $250–$400 permit and ~$3,500 ductwork totals $5,650–$9,800 before options.1 Our addition of their line items.
FAQ
How long does HVAC installation take? Three to five days when ductwork is included; a straight unit change-out is faster.2
What size system does my house need? Roughly 1.5 tons per 600–1,000 sq ft as a starting point, but insulation, windows and climate zone move the number — a proper load calculation beats any rule of thumb.1
Should I replace the furnace and AC together? It is usually cheaper than two separate visits, and matched systems run more efficiently. HomeGuide’s $5,000–$11,000 replacement figure assumes both.2
When do ducts need replacing too? Ducts last 10 to 20 years; expect duct work when the system is over 15 years old or you are upsizing.2
Why is my 2026 quote so much higher than a few years ago? SEER2 efficiency rules effective January 2023 raised equipment prices roughly 15% to 20%, on top of normal inflation.3
Sources
- Angi, How Much Does HVAC Replacement Cost? (2026 data).
- HomeGuide, How Much Does a New HVAC System Cost to Install or Replace? (2026).
- Fixr, Cost to Install Central Air (updated August 2025).
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