HVAC Replacement Cost Calculator

HVAC replacement is the second-biggest capex after the roof on most homes. This calculator sizes the installed budget across central AC, heat pump, geothermal, and mini-split systems with adjustments for SEER and ductwork.

System size (tons)

1 ton = 12,000 BTU

System type

SEER rating

Ductwork

Region cost factor

Estimated total

$7,700

installed

Low end

$6,545

High end

$9,240

Equipment cost

$5,200

unit only

Ductwork cost

How the math works

Central AC + furnace typically runs $6,000–$12,000 installed. Heat pumps add $1,500 to that range but replace both heating and cooling. Geothermal is 2–3× but operating cost is 50% lower and federal tax credits can offset 30% of the install.

SEER ratings above 18 add diminishing returns in most climates. Variable-speed and two-stage compressors improve comfort more than raw efficiency at that point. Match the system size to a Manual J load calculation, not to the existing unit.

How to Use

Size the system in tons. 1 ton per 500–700 sq ft is a rough rule; a Manual J load calc is better.
Pick a system type. Heat pumps replace furnace and AC; mini-splits eliminate ductwork; geothermal has 2–3× upfront cost but lower lifecycle cost.
Set SEER rating. 14 is the 2023 federal minimum in the South; 15 in the North. 18–20 is a comfortable premium tier.
Indicate ductwork condition. New ductwork adds $4,000–$8,000 but often cuts operating cost by 15%.
Adjust region factor up for California, NYC, and other HCOL metros.

Frequently Asked Questions

Heat pump vs central AC + furnace?

Heat pumps win in moderate and increasingly cold climates. Federal IRA tax credits up to $2,000 plus state rebates often close the upfront gap. Operating cost is lower than resistance electric and competitive with gas at current prices.

Is geothermal worth it?

With the 30% federal tax credit and typical payback of 10–15 years, geothermal makes sense on long holds (25+ years) or when running new construction that avoids retrofit ductwork. Operating cost is the lowest of any option.

How long does a new HVAC last?

Central AC and heat pumps: 12–18 years. Furnaces: 18–25 years. Geothermal indoor components: 20–25 years; loop: 50+. Matched system components (same manufacturer, year) live longer than mixed.

What if my ductwork is leaky?

Leaky ducts can lose 25–40% of conditioned air before it reaches rooms. Sealing costs $400–$1,500 and typically pays back in 2–4 years of energy savings. Consider before sizing up equipment.