Central AC replacement cost calculator (2026)

How this estimate is built

Installed central AC pricing in 2026 scales mainly with tonnage and efficiency tier. A code-minimum 14.3–15 SEER2 system runs roughly $1,900–$2,600 per ton installed; a 16–17 SEER2 two-stage system $2,300–$3,100 per ton; and an 18+ SEER2 variable-speed system $2,900–$4,000 per ton. A typical 3-ton, mid-tier replacement therefore lands in the $7,000–$9,500 range — condenser, matched indoor coil, line-set flush or replacement, new pad, disconnect, refrigerant, startup, permit, and labor. Small systems carry a floor around $4,200 because the labor doesn't shrink with the equipment.

Two things get added on top and are often where the real money is. Ductwork: sealing and repairing leaky ducts is $800–$2,500; replacing a duct system is $3,000–$7,000 and, in an older house, may be the single most valuable part of the job. And the furnace or air handler: if it's over 15 years old, replacing it at the same time ("full system") adds $3,000–$6,500 but avoids paying a second labor charge and a second coil-matching problem in a few years.

What tonnage you actually need

The square-footage ranges next to each size are a sanity check, not a sizing method. Insulation, windows, orientation, ceiling height, and climate move the right answer by a full ton either way. A reputable installer performs a Manual J load calculation; an installer who quotes the same size as the old unit without measuring anything is guessing, and oversized AC is a common, expensive mistake — it short-cycles, dehumidifies poorly, and wears out early. Ask for the Manual J. If they don't do one, that's a quote to skip.

Base, mid, or high efficiency?

In a hot climate with long cooling seasons, the jump from base to mid tier typically pays back in 5–8 years on energy alone and is worth it; the jump to 18+ SEER2 variable-speed buys comfort (quieter, steadier humidity) more than it buys payback. In a mild climate, base or mid is the rational choice. Note that 2025–2026 equipment uses the newer R-454B or R-32 refrigerants; that's fine, but it means your old R-410A line set may need replacing rather than flushing — a $300–$900 item some quotes bury.

Repair or replace?

Under 10 years old with a single failed part — capacitor, contactor, fan motor — repair. Over 12–15 years, on R-22 refrigerant, or facing a compressor or coil replacement, replace: those repairs run $1,500–$3,500 on a system that's near the end anyway. The AC repair-or-replace guide has the $5,000 rule and the age table.

Getting quotes

Get three, in the shoulder season if you can (spring and fall quotes run 10–20% under July). Each quote should name the exact outdoor and indoor model numbers (so you can verify the AHRI-matched efficiency rating), state the SEER2, include a Manual J, itemize ductwork and line-set work, and spell out the labor warranty separately from the parts warranty. HVAC quotes on identical work routinely vary 40%; this is the trade where the third quote most often saves four figures.