Last updated: July 16, 2026 · Prices reviewed quarterly
Replacing a central AC unit costs $6,600 to $12,000 for most homes in 2026, with the full realistic range at $3,500–$14,000 depending on tonnage, SEER2 rating and what your ductwork needs. A common job — 3-ton, 16 SEER2, on a 1,800–2,200 sq ft house — lands at $6,500–$9,000 installed. Equipment is roughly half the bill; labor, line sets, electrical and permits are the other half nobody itemizes until you ask.
AC unit replacement cost by system size (tonnage)
| System size | Home size (approx.) | 2026 installed cost |
|---|---|---|
| 2 ton | 900 – 1,300 sq ft | $3,200 – $6,500 |
| 3 ton | 1,600 – 2,200 sq ft | $6,500 – $9,000 |
| 4 ton | 2,200 – 2,800 sq ft | $6,500 – $9,800 |
| 5 ton | 2,800 – 3,500 sq ft | $7,800 – $12,000 |
Ranges compiled from 2026 pricing at HomeGuide and HVAC industry cost data; exact sizing depends on a Manual J load calculation, not square footage alone — insist on one.
SEER2: where efficiency stops paying
Federal minimums are now 14 SEER2 in the South/Southwest and 15 SEER2 in the North. Installed pricing stacks roughly like this: 14 SEER2 at $3,800–$5,500, 16 SEER2 at $4,500–$7,200, 18 SEER2 at $6,000–$10,000+. For most homeowners 16 SEER2 is the sweet spot: the 14→16 upgrade pays back in 5–9 years in hot climates. The jump to 18+ takes 12–20 years to recoup in most homes — buy it for comfort features (variable speed, humidity control), not for the math.
What drives the price up or down
Ductwork. Leaky or undersized ducts add $1,500–$5,000 — and skipping needed duct work strangles the new unit’s rated efficiency. Electrical. Older panels may need a new circuit or upgrade ($300–$2,500). Coil and line set. Matching the indoor coil is standard practice; reusing an old mismatched coil to save $800 usually costs more in efficiency and warranty disputes. Refrigerant transition. 2026 units use R-32/R-454B; quotes on leftover R-410A equipment should come discounted — ask. Season. Mid-heat-wave replacements pay peak labor; shoulder-season (spring/fall) installs are where discounts live.
Repair or replace?
Use the 5,000 rule: multiply the repair quote by the unit’s age — over $5,000, replacement wins. A $600 capacitor on a 6-year-old unit: repair. A $2,200 compressor on a 14-year-old R-410A unit: replace. Diagnose the actual fault first — our guide to why your AC isn’t cooling separates $150 fixes from real failures, and a $70–$200 tune-up each spring stretches the decision years. Replacing furnace and AC together? Price the combo — see full HVAC replacement costs — and if you’re electrifying, compare a heat pump installation before buying cooling-only.
How to save money
Get three itemized quotes naming brand, model numbers, SEER2, and every line item (permit, disposal, thermostat, duct sealing). Check utility rebates on DSIRE before choosing efficiency tier — a $500–$1,200 rebate often moves the 16 SEER2 tier below a 15. Schedule for shoulder season. And reject “per-ton flat pricing” quotes that skip the load calculation — oversized units short-cycle, wear early and dehumidify badly.
Official resources & free help
LIHEAP — federal cooling/heating bill and equipment assistance for eligible households: 1-866-674-6327.
2-1-1 (United Way) — local HVAC repair assistance programs: dial 211.
ENERGY STAR — certified equipment lists and sizing guidance: energystar.gov.
DOE Energy Saver — central AC buying and efficiency guides: energy.gov/energysaver.
DSIRE — state and utility rebate database: dsireusa.org.
Frequently asked questions
How much does it cost to replace an AC unit in 2026?
Most central AC replacements run $6,600–$12,000 installed; simple 2-ton swaps start near $3,200–$3,500 and large high-efficiency systems reach $14,000, per HomeGuide’s 2026 data.
Should I replace my 20-year-old AC that still works?
If it runs, plan rather than panic: get shoulder-season quotes now so a failure never forces an emergency purchase. Efficiency alone rarely justifies replacing a working unit — but any major repair on a 15+ year system does.
What SEER2 rating should I buy?
16 SEER2 balances price and payback for most homes. Go higher only in very hot climates with long cooling seasons or for comfort features like variable-speed compressors.
How long does AC replacement take?
A straight condenser-and-coil swap: one day. Add duct repairs, electrical work or a full air handler and it stretches to 2–3 days plus inspection.
Is it cheaper to replace the AC and furnace together?
Usually yes when the furnace is 12+ years old — shared labor, one permit round and matched equipment typically save $1,000–$2,500 versus two separate projects.
Prices on this page are researched estimates compiled from the cited sources; your local costs will vary with market, access and scope. Always get multiple written quotes from licensed professionals before hiring.