HVAC Replacement Cost Calculator
Updated · By the CalculatorDash editorial team · How we check our maths
Quick answer
A replacement system is sized at roughly one ton of cooling per 500–600 sq ft. For a 2,000 sq ft home that's about a 4-ton system; a standard-efficiency AC and furnace replacement usually lands around $15,000–$19,000 installed, and a heat pump somewhat more before rebates.
How this calculator works
HVAC replacement is priced mainly by capacity. Contractors size cooling in tons, where one ton moves 12,000 BTU of heat an hour, and a rough rule is one ton for every 500–600 square feet depending on climate. The calculator rounds up to the next half ton, the steps equipment is sold in.
System type multiplies the equipment cost: a furnace alone is the cheapest, an AC plus furnace pair or a heat pump that heats and cools costs the most. Higher efficiency (SEER2 and AFUE ratings) and variable-speed equipment cost more upfront and less to run.
Ductwork is the wild card. Reusing sound ducts costs nothing extra; sealing leaky ducts is a modest add-on; replacing a whole duct system can add several thousand dollars. For contractors, the per-ton price and base labor are hidden owner settings, so customers see a clean estimate.
The formula
- Size
- home sq ft ÷ sq ft per ton for the climate, rounded up to the next half ton
- Equipment
- tons × price per ton × system multiplier × efficiency multiplier
- Installed price
- equipment + base labor + ductwork + thermostat
Worked example
A 2,000 sq ft home in a moderate climate needs about 4 tons (2,000 ÷ 550 = 3.6, rounded up to the next half ton). An AC + furnace at standard efficiency is 4 × $1,900 × 1.8 = $13,680 of equipment, plus $3,000 labor and a $300 smart thermostat: about $16,980, shown as a range of roughly $14,900–$19,000.
Tips
- 01Ask for a Manual J load calculation; oversized systems short-cycle, feel clammy and wear out faster.
- 02Check federal, state and utility rebates for heat pumps and high-efficiency equipment before choosing.
- 03Replacing the AC and furnace together usually costs less than doing them a few years apart.
Frequently asked questions
How much does it cost to replace an HVAC system?
For a typical US home, roughly $8,000 to $20,000 installed depending on size, system type, efficiency and ductwork.
What size AC do I need?
As a rule of thumb, one ton per 500–600 sq ft. A contractor's load calculation is the reliable answer.
Is a heat pump worth it?
In many climates yes: it heats and cools with one system and is far more efficient than electric resistance heat. Rebates often close the price gap.