calcnet
All calculators

Home & DIY · Cost

HVAC Replacement Cost Calculator

Estimate what a new furnace, AC, heat pump, or mini-split should cost installed — by system type, efficiency, home size, ductwork, and region. You get a low-to-high price range with the equipment and ductwork broken out.

Inputs

Result

Adjust the inputs to see your result.

How the estimate works

Each HVAC system type has a national whole-job installed range that already blends the equipment and the contractor's labor — from about $2,000–$5,000 for a single-zone mini-split up to $6,000–$13,000 for a full AC-and-furnace replacement. The calculator starts from that range for the system you pick, then scales it by efficiency tier, home size, and your region.

High-efficiency equipment multiplies the range by about 1.4×; a small home trims it, a large home raises it; and your region swings labor and equipment prices up or down. Ductwork is handled separately — sealing or repairing existing ducts adds a little, while brand-new or full-replacement ductwork adds roughly $2,000–$5,000 on top. The result is an honest low-to-high range, because real HVAC bids vary that much.

What drives the price

  • System type is the biggest lever — a full system or multi-zone mini-split costs two to three times a single AC unit.
  • Efficiency adds roughly 40% for high-SEER2 / high-AFUE equipment, recovered over years through lower bills.
  • Ductwork is the wildcard. New duct runs in a home that never had them is the most common budget-buster.
  • Region and home size shift both the equipment tonnage you need and the local labor rate to install it.

Common mistakes

  • Sizing by rule of thumb. Insist on a Manual J load calculation — an oversized system short-cycles, leaves the air humid, and wears out early. Our Room BTU Load Calculator is a good sanity check.
  • Forgetting ductwork and the thermostat. Leaky ducts can waste 20–30% of your conditioned air; budget for sealing even if you keep the runs.
  • Replacing only half a system. Pairing a new AC with an old furnace coil can hurt efficiency and void warranties — match the components.
  • Taking one bid. HVAC bids for the same job routinely vary 30% or more. Always get three.

When this calculator is the wrong tool

Use an in-home load calculation and contractor walkthrough for: exact equipment tonnage, geothermal or hydronic systems, commercial rooftop units, or zoning and ductwork redesign. This tool estimates a standard residential replacement so you can budget and judge whether the bids you get are reasonable.

Recommended

Recommended for this job

We may earn a commission on qualifying purchases. Prices and availability are set by the vendor.

FAQ

Questions, answered

How much does it cost to replace an HVAC system?
It depends on what you're replacing. A central AC unit runs about $3,500–$7,500 installed; a gas furnace $3,000–$6,500; a full AC-plus-furnace system $6,000–$13,000; a heat pump $4,500–$11,000. High-efficiency equipment, a larger home, new ductwork, and high-cost metros push you toward the top of each range.
Is an AC or a heat pump cheaper to install?
A standalone central AC ($3,500–$7,500) is usually cheaper up front than a heat pump ($4,500–$11,000), but the heat pump replaces both your heating and cooling in one system. If you'd otherwise be paying for AC and a furnace, a heat pump can be the better total value — especially in mild climates where it runs efficiently year-round.
Is a high-SEER2 system worth the extra cost?
High-efficiency equipment costs roughly 40% more up front and pays that back through lower energy bills over years, not months. It's worth it if you're staying in the home 7+ years, run your system hard (hot or cold climate), or qualify for a rebate or tax credit. For a home you'll sell soon, standard efficiency usually makes more sense.
Does new ductwork add a lot to the price?
Yes — figure roughly $2,000–$5,000 for new or full-replacement ductwork on top of the equipment, depending on home size, layout, and access. Sealing or repairing existing ducts is much cheaper (often under $1,200). Always have ductwork itemized separately on each bid so you can compare apples to apples.
How much does it cost to replace a furnace and AC together?
A combined AC-and-furnace replacement typically runs $6,000–$13,000 installed. Doing both at once usually costs less than two separate jobs and lets the installer properly match the coil, blower, and refrigerant charge. Only replace both if both are actually near end of life — a working furnace doesn't need to go just because the AC died.