HVAC Replacement Cost Calculator
Estimate the cost of replacing a central HVAC system based on home size and system type.
Enter your values and click Calculate
Replacing an HVAC system is a major home improvement project that affects comfort, energy bills, and indoor air quality for the next 15–25 years. The total cost depends on your home's square footage, the type of system being installed, and the efficiency rating of the new equipment. Central AC-only replacements apply to homes in warmer climates that rely on a separate furnace for heating and only need the cooling unit swapped out. Furnace-only replacements address homes where the air conditioning is still functional and only the heating unit has reached end of life. A full HVAC system replacement — both the air conditioner or heat pump and the furnace — is the most comprehensive scenario and often makes financial sense when both units are aging. Heat pumps are an increasingly popular alternative that provides both heating and cooling from a single unit by moving heat rather than generating it, making them highly efficient in moderate climates. Higher efficiency ratings (measured in SEER for cooling and AFUE for heating) carry a higher equipment cost but reduce monthly utility bills over the system's lifetime. Installation costs include equipment, refrigerant, electrical connections, and basic ductwork attachment. Major duct repairs or replacements are typically quoted and billed separately.
How It Works
Base cost is calculated by multiplying home square footage by a per-square-foot rate that reflects the system type: $3.50/sq ft for AC only, $2.80/sq ft for furnace only, $6.00/sq ft for a full HVAC system, and $5.00/sq ft for a heat pump. This base cost is then multiplied by the efficiency factor — standard at 1.0x, high efficiency at 1.3x, and ultra-high efficiency at 1.6x. The low estimate is 75% of the midpoint; the high is 135%. HVAC pricing is especially variable because equipment costs fluctuate with supply chains, labor rates vary significantly by region, and system sizing (tonnage) depends on factors like insulation and window area that square footage alone does not capture. Multiple contractor quotes are strongly recommended.