Air Conditioning Installation Cost Calculator

Cooling capacity is measured in tons (12,000 BTU each), and the rule of thumb is roughly one ton per 400–600 square feet — so a 2,000 sq ft home often lands around 3.5–4 tons. But square footage is only the starting point the calculator uses to estimate cost. Proper sizing comes from a Manual J load calculation that also weighs your climate, insulation, windows, ceiling height, and sun exposure. Sizing matters more than people think: an undersized unit never keeps up on hot days, while an oversized one short-cycles, wastes energy, and leaves the air clammy because it doesn't run long enough to dehumidify. Always have a contractor confirm the tonnage before buying equipment.

Central AC (a split system with an outdoor condenser and an indoor coil) is the standard for homes that already have ductwork — it cools the whole house evenly and is the cheapest per square foot to install when ducts exist. A ductless mini-split skips ducts entirely, using one or more wall-mounted indoor heads, which makes it ideal for homes without ductwork, additions, garages, or room-by-room zoning. A heat pump installs like central AC or a mini-split but runs in reverse in winter to also heat the home — one efficient system for both seasons, increasingly popular even in cold climates. The calculator's System Type selector prices all four (including budget window/portable units) so you can compare them for your square footage.

Because installing a duct system from scratch is its own major project — running supply and return trunks, branch runs, registers, and returns through walls, ceilings, and floors, then sealing and balancing it. In this calculator new ductwork adds about $3 per square foot, which on a 2,000 sq ft home is roughly $6,000 on top of the equipment. That's exactly why ductless mini-splits are so popular in homes without ducts: a mini-split often costs less overall than central AC plus a new duct system. If you already have sound ducts (say, from a furnace), the AC reuses them and the Ductwork selector adds nothing.

It depends on your climate and how hard the system works. High-efficiency units cost roughly 30% more upfront but use less electricity, run more quietly, and control humidity better. In hot regions where the AC runs heavily for months, the lower bills can recoup the premium over the system's life — especially with utility rebates or federal tax credits, which many high-SEER2 and heat-pump systems qualify for. In a mild climate with light use, a standard-efficiency unit is often the better value. High-efficiency models also tend to carry longer warranties. Toggle the Efficiency selector to see the upfront difference, then weigh it against your cooling season.

Often, yes, for a central system. The AC's indoor coil sits on top of the furnace, and they share the blower and ductwork — so if the furnace is also aging, replacing both together saves on labor (one project, not two), ensures the components are matched for rated efficiency, and avoids a second disruptive install in a few years. Matched systems also qualify for better efficiency ratings and rebates. If your furnace is newer and in good shape, replacing just the AC is fine. A heat pump is worth pricing here too, since it can replace both the AC and much of the furnace's job in one system.

For any permanent system, yes. Installing or replacing central AC, a mini-split, or a heat pump typically requires a mechanical (HVAC) permit and often an electrical permit, plus inspection — the work involves refrigerant, line sets, and electrical connections that must meet code. Handling refrigerant also legally requires EPA Section 608 certification, so this is professional work, not DIY. A licensed HVAC contractor pulls the permits and schedules the inspections as part of the job; the calculator includes a Permit & Inspection add-on. Only plug-in window or portable units need no permit. Skipping permits can void equipment warranties and create problems with insurance and home sales.

A straightforward central AC replacement that reuses existing ductwork is usually a single day (about 4–8 hours). A ductless mini-split with one or two zones is also often a one-day job; more zones add time. The big jump is installing central AC in a home with no ducts — adding the duct system can take several days on top of the equipment install. Heat-pump installs mirror the equivalent AC type. Electrical upgrades, a new pad and line set, or permit inspections can add time. Most simple replacements finish in a day, while new-ductwork or multi-zone projects run several days.

A complete installation is more than dropping in a condenser. It typically includes setting the outdoor unit on a pad, the indoor coil or air handler, the refrigerant line set, an electrical disconnect and circuit, a condensate drain, a thermostat, refrigerant charge, and a startup/commissioning check — plus permits and inspection. The calculator breaks the common variables into add-ons: an electrical/disconnect upgrade, a new condenser pad and line set, removing and disposing of the old unit, a smart thermostat, a zoning system, and the permit. Reusing a sound pad, line set, and thermostat keeps the cost down; replacing them (recommended on older systems) adds to it.

Same tonnage rarely means same job. The variables that move two otherwise-identical quotes are the system type and efficiency (a high-SEER2 heat pump costs far more than a standard central unit), whether ductwork was reused or newly installed, the condition of the existing line set, pad, electrical, and thermostat, the difficulty of the install location (attic, tight crawlspace, second-story heads), local permit fees, and regional labor rates — which this calculator adjusts by ZIP. Add-ons like zoning or an electrical upgrade also swing the total. Comparing quotes only works when the equipment, efficiency, and scope of work match line for line.

Usually, if it's in good shape. Reusing sound ducts is the single biggest way to keep a central AC install affordable — it's why the Ductwork selector adds nothing for 'existing ducts.' But old ductwork should be inspected first: leaky, undersized, crushed, or poorly sealed ducts waste a large share of your cooling and can leave rooms uneven, undercutting even a brand-new high-efficiency unit. A contractor may recommend sealing, repairing, or partially replacing ducts rather than a full new system. If the ducts are beyond saving, a ductless mini-split is often the more economical path than tearing out and rebuilding the duct system.