Last updated: July 7, 2026 ยท Prices reviewed quarterly
A central AC replacement costs $3,000 to $15,000 installed in 2026, with most homes landing between $4,000 and $9,000 depending on tonnage and efficiency. The right size comes from a load calculation — oversizing is the most expensive “upgrade” you can buy.
Cost by home size
| Home size | Typical unit | Installed cost (2026) |
|---|---|---|
| ~1,200 sq ft | 2 ton | $3,000 – $5,500 |
| ~1,800 sq ft | 3 ton | $4,000 – $7,000 |
| ~2,400 sq ft | 4 ton | $5,000 – $9,000 |
| High-SEER / variable premium | any | $9,000 – $15,000 |
SEER math without the sales pitch
Each SEER2 point saves roughly 5-8% on cooling energy. Jumping from a failing SEER 10 unit to the modern baseline cuts cooling bills 35-40% by itself; paying $3,000+ extra to go from 16 to 21 SEER2 only pencils in hot climates with long seasons and high rates. Run YOUR numbers, not the brochure’s.
Replace now or repair once more?
Under 8 years — repair. 8-12 — repair if minor. 12-15 — lean replace. Over 15 — replace. Tiebreaker: repair cost × unit age > ~$5,000 → replace. A $900 repair on a 9-year unit ($8,100) says replace; the same repair at year 4 says fix. Failure prices: AC not cooling guide.
Quote red flags
Sizing without a Manual J. “Free” upgrades folded into inflated totals. Refusal to itemize equipment vs labor. Sign-today “truck discounts.” Reused line sets on incompatible refrigerants. Any of these → next contractor. Full-system context: HVAC replacement costs.
Official resources & free help
- Efficiency ratings explained: EnergyStar.gov
- Utility rebates for high-SEER units: DSIRE database
- Cooling assistance: LIHEAP 1-866-674-6327
- Sizing sanity check: Energy.gov central AC guide
FAQ
Same tonnage, quotes $4,000 apart?
Efficiency tier, brand line, and whether coil, line set, pad and electrical are included. Force apples-to-apples itemization.
Can I replace just the outdoor unit?
Rarely advisable now — coil compatibility and refrigerant changes usually force a matched pair.
Best time of year to buy?
Shoulder seasons. Emergency July replacements pay peak premiums — the plan-ahead math favors acting at year 12-13, not at failure.
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.