HVAC Replacement Cost Calculator
This tool helps you plan the cost of replacing an HVAC system before you meet with a contractor. Enter your home's floor area and the work you expect. The result shows equipment costs and duct costs separately, so you can see what a quote may leave out.
1Size the project
This rough size is only used to plan cost. Ask for a Manual J load calculation before choosing equipment.
2Price the scope
Use 100 for a national planning range. Many high-cost cities may be closer to 115–140.
Planning range
$7,700–$14,200
The middle of this range is about $11,000, before rebates or financing.
Rough size used for cost
3.5 tons
A Manual J result may be lower or higher.
Equipment + installation
$7,700–$14,200
Duct cost allowance
$0
This includes only the duct work chosen above.
Compare this range with two or three local quotes that list each cost. The estimate may not include permits, electrical service work, fuel changes, asbestos, cranes, or zoning.
Inputs stay in this browser. No account or quote request is required.
Quick planning answer
Replacing both a furnace and central AC often costs from the high thousands to the middle tens of thousands of dollars. Major ductwork can add more. System size, efficiency, local labor, access, controls, and electrical work all affect the price.
Start with a clear list of the work
A quote should list what is included. Look for the indoor unit, outdoor unit, coil, thermostat, pad, refrigerant lines, disconnect, drain, vent parts, and permits. If the furnace and AC share a cabinet, replacing only one part may still require new connections and control changes.
The tonnage shown here is only used to plan cost. Floor area alone cannot account for sunny windows, attic air leaks, shade, people, or duct losses. Before choosing equipment, ask the contractor for an ACCA Manual J load calculation. Then compare the home's heating and cooling load with the equipment's rated output.
Why prices vary so much
Variable-capacity equipment costs more and often needs a special thermostat. Tight crawlspaces, rooftop lifting, drain repairs, a new flue liner, or a crowded electrical panel also add labor. National averages may not include these problems.
- Get a written AHRI equipment match with model numbers for each main part.
- Ask for each duct repair to be listed by location.
- Ask how the contractor will test static pressure, refrigerant charge, airflow, temperature change, combustion, and controls.
- Confirm who gets the permit, removes old refrigerant, and registers the warranty.
Use the range to compare quotes
Make sure every quote covers the same work. One contractor may include a large filter, surge protector, crane, permit, and labor warranty. Another may charge for those later. Small model-number changes can also affect cold-weather heat-pump output or furnace airflow.
If a quote falls outside this range, ask why. The contractor should be able to name the extra cost and show it as a line item. Before your system fails, save its age, model numbers, filter size, and photos of the electrical panel. That information can help you avoid a rushed choice.
Questions people ask before buying
How much does it cost to replace a furnace and AC together?
A basic standard-efficiency replacement often costs about $8,000 to $16,000. Prices can be higher in costly markets or when the job needs variable-capacity equipment, hard access, code fixes, or major ductwork. Enter your project details for a closer range.
Is it cheaper to replace the furnace and AC at the same time?
It can be. The two systems share some labor and parts. But keeping a newer part can still make sense if it works with the new equipment and has a good coil, refrigerant type, controls, and warranty.
Does this calculator choose the HVAC size?
No. It uses a rough system size only to plan cost. Final sizing needs a room-by-room Manual J load calculation, the maker's equipment data, and a duct check or design.
Should duct replacement be in the HVAC quote?
Yes, if the job needs it. The quote should list new connections, a larger return, damaged ducts, leak repairs, or full replacement. New equipment may still be noisy or uncomfortable when connected to ducts that leak or block airflow.
Method, sources and limits
The tool uses conditioned floor area and one of three climate groups to find a rough system size. Each system type has a low and high base cost. Larger systems cost more. Efficiency, access, and local prices also change the range.
Duct repairs and replacement are shown as separate costs. The estimate does not include rebates, financing, unusual hazardous-material work, electrical service upgrades, fuel changes, zoning, cranes, or structural repairs unless the access or duct choices cover them.
- Residential HVAC design manuals (Air Conditioning Contractors of America)
- Ductless heating and cooling: proper sizing (ENERGY STAR)
- Consumer central air conditioners and heat pumps (U.S. Department of Energy)