Central AC Installation Cost by Tonnage (2026)
| System Size | Approx. Home Size | Typical Installed | 2026 Range (standard tier) |
|---|---|---|---|
| 1.5 tons | ~825 sq ft | $4,500 | $4,000 - $5,000 |
| 2 tons | ~1,100 sq ft | $5,000 | $4,400 - $5,600 |
| 2.5 tons | ~1,375 sq ft | $5,500 | $4,800 - $6,200 |
| 3 tons | ~1,650 sq ft | $6,000 | $5,300 - $6,700 |
| 3.5 tons | ~1,925 sq ft | $6,700 | $5,900 - $7,500 |
| 4 tons | ~2,200 sq ft | $7,400 | $6,500 - $8,300 |
| 5 tons | ~2,750 sq ft | $8,500 | $7,500 - $9,500 |
All figures are installed prices for a like-for-like replacement - condenser, matched evaporator coil, labor, permit, and disposal - at the standard tier (single-stage, 14-15 SEER2) and national-average labor. The home-size column is an approximation only: confirm your real tonnage with the central AC size calculator or the tonnage per square foot chart before pricing, because roughly half of installed systems are oversized.
How Much Does It Cost to Install Central Air?
The cost to install central air splits into two very different questions. Replacing a system that already has ductwork runs $4,000 to $9,500 depending on size. Installing central air into a house that has never had it runs $11,000 to $17,900, because the ducts and the electrical come with it.
For the most common job, a 3-ton replacement at national-average labor, the number is $6,000 typical in a range of $5,300 to $6,700. The same 3 tons installed from scratch with a full duct system and a new circuit is $13,500. That gap of roughly $7,500 is ductwork and electrical, not equipment, which is why the first question any quote should answer is what condition your ducts are in.
2 Ton AC Unit Cost
A 2-ton central AC replacement is $5,000 typical, ranging $4,400 to $5,600, which works out to about $66 a month financed over ten years. At $2,500 per ton this is one of the more expensive sizes per unit of cooling, because the fixed costs of a job (crew day, permit, disposal, line set) barely change with tonnage. Suits roughly 1,100 sq ft.
2.5 Ton AC Unit Cost
A 2.5 ton AC unit cost is $5,500 typical installed, ranging $4,800 to $6,200, or about $72 a month financed. That is $2,200 per ton for roughly 1,375 sq ft. This is the size that gets rounded up most often, because a contractor with a 3-ton unit on the truck would rather sell that. A Manual J load calculation is what settles 2.5 against 3. The half ton is only $500 on the quote, and the cost of taking it shows up later as a system that cools fast and leaves the air damp. For reference, the 2.5 ton AC unit installed price is $500 above the 2 ton AC unit installed price and $500 below the 3 ton.
3 Ton AC Unit Cost
The most quoted size in American homes. A 3-ton replacement runs $6,000 typical ($5,300 to $6,700), about $79 a month financed, covering roughly 1,650 sq ft. It is also the size most often sold to houses that needed 2.5, so before accepting a 3-ton quote, confirm the load rather than the square footage. An oversized system costs more at install and then again every month it short cycles.
3.5 Ton AC Unit Cost
A 3.5 ton AC unit cost is $6,700 typical installed ($5,900 to $7,500), about $88 a month financed, for roughly 1,925 sq ft. The step from 3 tons is $700, the largest jump so far, because the bigger condenser usually brings a larger coil and a heavier electrical circuit with it. A 2,000 sq ft house in a mixed climate lands here.
4 Ton AC Unit Cost
A 4-ton system is $7,400 typical ($6,500 to $8,300), around $97 a month financed, for roughly 2,200 sq ft. This is where the existing ductwork starts to matter mechanically rather than just financially: a duct system sized years ago for a smaller unit will not carry 1,600 CFM quietly, and the fix is trunk work rather than a bigger condenser.
5 Ton AC Unit Cost and Why Bigger Is Cheaper per Ton
Five tons is the top of residential at $8,500 typical ($7,500 to $9,500), about $112 a month financed, for roughly 2,750 sq ft.
It also shows the pattern running through this whole table. Cost per ton falls steadily as the system grows: $3,000 per ton at 1.5 tons down to $1,700 per ton at 5. That is not a reason to buy bigger. It is the reason an oversized system looks like good value on the quote and then is not, because the running cost and the short cycling follow the capacity rather than the price per ton.
Central Air Conditioner Prices: Unit Only vs Installed
Central air conditioner prices online are usually for the box, and the central air conditioner installation cost is for the job, which is why the two never match. The calculator splits every installed price into two lines, and this is that split at each size.
| Size | Installed Price | Equipment and Materials | Installation Labor |
|---|---|---|---|
| 1.5 tons | $4,500 | $2,500 | $2,000 |
| 2 tons | $5,000 | $3,000 | $2,000 |
| 2.5 tons | $5,500 | $3,500 | $2,000 |
| 3 tons | $6,000 | $4,000 | $2,000 |
| 3.5 tons | $6,700 | $4,700 | $2,000 |
| 4 tons | $7,400 | $5,400 | $2,000 |
| 5 tons | $8,500 | $6,500 | $2,000 |
The equipment and materials line is not the central air unit cost on a pallet. It holds the condenser, the matched indoor coil, the line set, the pad, the refrigerant, the permit and the contractor's overhead. Owners who have priced the hardware alone put a condenser at $2,000 to $3,000 depending on size and efficiency, and a new outside AC unit cost on its own is only the full answer when the indoor coil is recent enough to keep.
Tip: compare installed prices with installed prices. A unit-only figure set against a contractor's quote will always make the quote look padded, and most installers will not warranty equipment they did not supply.
Central Air Installation Labor Cost
Central air installation labor cost is about $2,000 of a $6,000 replacement in an average market, and the labor cost to install AC unit sizes from 2 tons to 5 is that same $2,000. A crew needs much the same day to recover the old refrigerant, set the condenser, fit the coil, braze the lines and pull a vacuum, whatever the capacity. What changes the labor is where you live.
| Where You Live | Installed Price | Of Which Labor |
|---|---|---|
| Lower-cost area (rural South / Midwest) | $5,100 | $1,700 |
| Average US market | $6,000 | $2,000 |
| High-cost metro (Northeast, West Coast) | $7,200 | $2,400 |
| Very high (NYC, SF, Seattle, Boston) | $8,100 | $2,700 |
Labor here is the installers' time at your house. One owner worked a $7,000 quote backwards, took off the hardware, and decided the rest came to $250 an hour for two people. It does not, because that remainder also pays for the truck, the insurance, the warranty visits and the office, and those sit in the other line. The average price for central air installation, the $6,000 in the second row, moves $900 down or $2,100 up with the market.
Tip: a quote with labor far above these figures is pricing extra work, so ask what it is. A new line set, a relocated condenser or a tight attic are fair reasons. No reason at all is not.
Four Things to Check Before You Price It
The price above assumes a straightforward job. Four things decide whether yours is one, and finding out afterwards is how a $6,000 quote becomes a $12,000 one. Take them in this order, because the first is the one that changes everything. They also explain why answers to how much to install central air vary so widely, and why any cost of installing central air conditioning system figure you read online is a range rather than a number: it depends less on the equipment than on what the house makes you do to fit it. A straight central ac replacement cost, swapping like for like where everything already fits, sits at the bottom of any range you read.
1. Do you already have ducts? If ducts and registers exist and are in reasonable condition, you are buying equipment and a day of labor, which is the price above. If the house never had them, you are buying construction: soffits, lost closet space, opened ceilings. Sealing and minor modification runs about $2,000; a full duct replacement is around $6,500, and that is on top of the equipment. This single question is worth more than every other variable combined, and it is why a house without ducts is usually better served by ductless.
2. Will your electrical panel take it? A central AC needs a 240 volt circuit of its own plus an outdoor disconnect, and this is the check people skip. If your panel is 100 amps and your stove, dryer and water heater are electric, there may be nothing left to give and you are looking at a panel swap or a subpanel. If those appliances run on gas, 100 amps is often fine. Budget about $1,000 for the circuit, disconnect and panel work; a full service upgrade is its own job on top. Ask an electrician before you accept an AC quote, not after, because the AC contractor may not price it at all.
3. Permits. Nearly everywhere requires one for new AC, and it usually covers both the mechanical and electrical work. A permitted job means an inspection, which is protection rather than red tape: it is the mechanism that catches an undersized circuit or a refrigerant line run badly. A contractor who suggests skipping the permit is telling you something about how the rest of the job will go.
4. Do not count on resale value paying for it. This gets oversold. A real estate appraiser put it plainly in a homeowner thread: central air alone does not make a large difference to what a house appraises for. In hot markets it affects how fast a house sells more than what it sells for, and in cool climates it can be close to neutral. Install it because you want to be comfortable, and treat any resale benefit as a bonus rather than the reason.
Cost of Central Air by House Size
Square footage is the number most people actually have to hand, and it decides the tonnage, which decides the price. So the useful way to ask how much is a central air unit installed is to ask it per house size, which is what the calculator at the top of this page does. Every row below comes straight out of it, set to a mixed climate with average insulation.
| House Size | Size Needed | Installed Cost |
|---|---|---|
| 1,000 sq ft | 2 tons | $4,400 - $5,600 |
| 1,200 sq ft | 2 tons | $4,400 - $5,600 |
| 1,500 sq ft | 3 tons | $5,300 - $6,700 |
| 2,000 sq ft | 3.5 tons | $5,900 - $7,500 |
| 2,500 sq ft | 4.5 tons, sold as 5 | $7,500 - $9,500 |
| 3,000 sq ft | Two systems | $7,500 - $9,500 each |
So the cost of central air for a 1,200 sq ft house is around $4,400 to $5,600, which buys a 2 ton central air conditioning unit, and the price to install central air in a 2,000 sq ft house is closer to $5,900 to $7,500. Those figures cover the outdoor unit and a matched coil at standard efficiency with your existing ducts reused. A 2 ton central ac and a 2 ton central air unit are the same thing quoted two ways, so do not read a difference into the wording on competing quotes. Three thousand square feet is the point where the math stops being a single row: the load runs past the 5 ton residential ceiling, so contractors quote two systems, which zones better and means a breakdown takes out half the house rather than all of it. Climate shifts every row, since the same house in Houston needs roughly half a ton more than in Seattle, and half a ton is several hundred dollars. Ductwork is the largest variable and it is deliberately not in these figures, because running ducts into a house that never had them is a different job with a different price.
What Moves a Central AC Quote Most
Three levers, and they are bigger than the difference between tonnages. All figures below are on the same 3-ton job.
- Ductwork condition, up to +108%. Ducts fine: $6,000. Sealing and plenum modifications: $8,000. Full replacement: $12,500. This is the single largest variable in central air pricing and the one least visible on a quote sheet.
- Region, up to +59%. The same job is $5,100 in low-cost rural markets, $6,000 at national average, $7,200 in Northeast and West Coast metros, and $8,100 in the most expensive cities.
- Efficiency tier, up to +45%. $6,000 standard single-stage, $7,200 two-stage, $8,700 variable-speed. Worth checking against the SEER savings calculator before paying it, because the payback period on the top tier is longer than most people assume.
Central AC Cost by Efficiency Tier and Size
Central AC cost by efficiency tier follows the same two steps at every size: two-stage is 20% over single-stage, and variable-speed is 45% over.
| Size | Single-Stage (14-15 SEER2) | Two-Stage (16-17 SEER2) | Variable-Speed (18+ SEER2) |
|---|---|---|---|
| 2 tons | $5,000 | $6,000 | $7,300 |
| 2.5 tons | $5,500 | $6,600 | $8,000 |
| 3 tons | $6,000 | $7,200 | $8,700 |
| 3.5 tons | $6,700 | $8,000 | $9,700 |
| 4 tons | $7,400 | $8,900 | $10,700 |
| 5 tons | $8,500 | $10,200 | $12,300 |
The premium grows with the unit, from $2,300 at 2 tons to $3,800 at 5, so a 5 ton AC unit price runs from $8,500 to $12,300, while the saving on the bill depends on how many hours a year the system runs. Tip: the top tier earns its price in long, hot summers and rarely anywhere else. In a mild climate, the single-stage unit and a careful installation is the better use of the money.
Cost of Installing Central Air for the First Time
Adding central air to a house that never had it is a much bigger job than swapping an old condenser, and the quotes reflect it. On top of the equipment, a first-time install needs a refrigerant line set run between the outdoor and indoor units, a condenser pad, a dedicated 240V circuit with an outdoor disconnect (about $1,000 of electrical work), and - the big one - ductwork. If the home has a furnace with usable ducts, you may only need sealing and modifications (about $2,000); with no ducts at all, a full duct system adds $6,500 or more.
Put together, installing central air from scratch in a typical 3-ton home runs roughly $11,900-$15,100, versus $5,300-$6,700 for a straight replacement. Set the ductwork and electrical options in the calculator above to price your scenario. If running ducts isn't practical, compare a multi-zone ductless system instead - our mini split AC calculator sizes one, and the HVAC replacement cost calculator prices single and multi-zone setups.
Adding AC to a Home That Has Ducts but No Cooling
The in-between case is extremely common in older homes: a furnace and working ductwork, but no air conditioning has ever been connected. It's cheaper than a from-scratch install because the ducts exist, but it's more than a swap - the crew still has to run the refrigerant line set into the house, mount and wire the outdoor unit on a new 240V circuit with a disconnect, add an evaporator coil to the furnace plenum, and route new thermostat wiring. (If fishing thermostat wire through finished walls is impractical, wireless communicating modules link the thermostat to the equipment without opening drywall.)
With ducts in good shape, that job runs about $6,200-$7,800 for a typical 3-ton system at the standard tier - select "Good - reuse as is" plus the electrical upgrade in the calculator. If the heating ducts need sealing and modifications to handle cooling airflow (they often do - cooling moves more air than heating), figure $7,900-$10,100. In higher-cost metros with mid-tier two-stage equipment, real-world quotes for these add-on projects commonly land in the $10,000-$15,000 range - the same numbers HVAC contractors quote on camera - which is exactly where the calculator goes when you set a high-cost region and mid efficiency tier.
How much to add central air, the cost to add central air to a home and the cost of adding central air to a house all turn on the ducts. With sound ducts and a new circuit a 3 ton job is $6,200 to $7,800. With duct repairs it is $7,900 to $10,100, and with no ducts at all it is $11,900 to $15,100.
Owner reports of the cost to install central air with existing ductwork sit in the same band, and this is what adding central air to a house cost four of them. One homeowner pricing the cost to add AC to existing furnace ductwork collected six quotes between $5,200 and $8,000. Another paid about $6,000 in 2022, a third paid $7,400, and a fourth was quoted $8,000 to $10,000 by several companies in a small mountain market. That range is the realistic cost to add AC to forced air system houses where the ducts are sound. The surprise in these stories is usually the panel rather than the AC: one owner with no free breaker slots was quoted $2,400 for a larger panel at the same amperage, after a first electrician had proposed a service upgrade at nearly $10,000.
Tip: get the electrical question answered by an electrician before you compare AC quotes. It is the one line that can double the job, and it is the one the AC contractor is least likely to have priced.
AC Replacement Cost: What It Costs to Replace an AC Unit in 2026
AC replacement cost is the lowest price on this page, because everything around the equipment is already in place. For a 3 ton home the cost to replace an AC unit is $5,300 to $6,700, and $6,000 is the average cost to replace AC unit and coil together at the standard tier. The same figure answers central air replacement cost, central AC replacement cost and air conditioner replacement cost, since they are three names for one job. Home AC replacement cost, central air conditioner replacement cost and the cost to replace central air unit equipment are the same again. Treat the calculator result as your AC replacement estimate before any contractor visits, and as the figure to hold each AC replacement quote against.
That price covers a new outdoor unit, a matched indoor coil, a flushed or new line set, a pad, the thermostat connection and about a day of labor. It assumes the ducts and the 240 volt circuit are reused. When either needs work the bill moves, and the table shows by how much.
4 Ton AC Unit Replacement Cost, and Every Other Size
| Size | Replacement, Ducts Reused | Typical | With Duct Repairs |
|---|---|---|---|
| 2 ton | $4,400 - $5,600 | $5,000 | $7,000 |
| 2.5 ton | $4,800 - $6,200 | $5,500 | $7,500 |
| 3 ton | $5,300 - $6,700 | $6,000 | $8,000 |
| 3.5 ton | $5,900 - $7,500 | $6,700 | $8,700 |
| 4 ton | $6,500 - $8,300 | $7,400 | $9,400 |
| 5 ton | $7,500 - $9,500 | $8,500 | $10,500 |
So the 4 ton AC unit replacement cost is about $7,400, the 3 ton AC unit replacement cost about $6,000 and the cost to replace 5 ton AC unit equipment about $8,500. At the small end, the cost to replace 2 ton AC unit equipment is about $5,000 and a 2.5 ton AC unit replacement cost is about $5,500. The 3.5 ton AC unit replacement cost comes to about $6,700. Each is a full AC replacement cost, outdoor unit and coil together, which some quotes call a complete AC unit replacement.
Drop the word unit and nothing changes. Read the 2 ton AC replacement cost and 3 ton AC replacement cost straight off the Typical column above, and the 4 ton AC replacement cost and 5 ton AC replacement cost further down it. That column is also the average cost of AC replacement at each size.
Owners often say the quote they were handed was thousands above a price they read online. Before you call it a bad quote, check that the two cover the same job. An online figure is usually the standard tier in an average-cost region with the ducts reused. Move any one of those and the price moves with it, which the calculator at the top will show you line by line.
Tip: a replacement quote far above the middle column is pricing something besides the AC. Ask which line it is. Duct repairs, a new circuit and a higher efficiency tier are the three usual answers, and each should appear as its own line.
Cost to Replace the Outside AC Unit Only
Some contractors will quote the outdoor AC unit replacement cost alone and leave the indoor coil in place. The outdoor unit is the condenser, so AC condenser replacement cost and the cost to replace an AC condenser describe this job too. A quote for it may read outside AC unit replacement cost or the cost to replace outdoor AC unit hardware. It is a real option when the coil is recent and uses the same refrigerant, and it is cheaper. We do not print a price for it, because the calculator prices the matched pair and a number for half the system would be a guess. An older system that runs on R-22 does not have this option, because new outdoor units use a different refrigerant, so the cost to replace an R22 air conditioner is the full matched price in the table above. Two cautions before you accept such a quote. A new outdoor unit on an old coil rarely reaches the efficiency on its label. And many makers will not honor the full warranty unless both halves are replaced together, so ask for that in writing.
New AC Unit Cost: What a New Air Conditioner Costs Installed
New AC unit cost and replacement cost are the same number when the house already has central air. The average cost of new AC unit and coil, installed, is about $6,000 for 3 tons at the standard tier. That is the new AC unit cost with installation, and the cost to install 3 ton AC unit equipment on existing ducts. The cost to install 4 ton AC unit equipment is about $7,400. By size, the new 2 ton AC unit cost is about $5,000, a new 3 ton AC unit cost is the $6,000 above, and a new 5 ton AC unit cost is about $8,500. Step up in efficiency and the new air conditioner cost rises to about $7,200 at the mid tier and $8,700 at the high tier.
What changes the new AC system cost most is whether it is truly new to the house. The new central air unit cost on existing ducts is the replacement price above, and so is the new AC installation cost. The new central air system cost in a house that has never had one is about $13,500 at 3 tons, because the ducts and the circuit are new as well. The section on first-time installs higher up this page breaks that second case down. By floor area, the cost of new AC unit for 1500 sq ft house use is about $6,000, and at 2,000 sq ft it is about $6,700. Central air unit prices without labor, the box alone, are in the unit-only table near the top.
Air Conditioning Replacement Estimate: What Contractors Include
When you collect quotes, make every air conditioning replacement estimate answer the same checklist: exact equipment model numbers (so you can compare tiers, not just brands, and decode the tonnage from the model number), the matched indoor coil, line-set replacement or flush, permit, disposal, and any duct or electrical work as separate line items. Quotes for the same house routinely differ by thousands purely on scope and brand tier - premium lines run 10-20% above the mid-tier prices this calculator uses, builder-grade about 10% below. (How we build the number - every base price and multiplier - is published in our cost model methodology.)
Two more levers worth checking before you sign: efficiency tier - a variable-speed 18+ SEER2 system costs about 45% more up front than single-stage, which the AC savings calculator can weigh against your electricity bill - and timing, since shoulder-season installs commonly come in 10-15% under peak-summer pricing. Replacing the furnace at the same time? Price the combo on the HVAC replacement cost calculator, or a heating-only job on the furnace replacement cost calculator.
And once the job is done, verify it before the crew leaves. A healthy system shows a roughly 15-20°F temperature differential between the return air going in and the supply air coming out of the vents. The outdoor disconnect should be mounted within arm's reach of the condenser, and the breaker must match the new unit's spec - modern inverter systems often need a much smaller breaker than the unit they replace (a 15-amp breaker replacing a 50-amp one is not a mistake), and an oversized breaker won't protect the equipment. If the new indoor coil or air handler sits shorter than the old one, a proper sheet-metal or duct-board transition sealed with mastic should bridge the gap - not tape alone.
Mini Split vs Central Air: Which Costs Less to Install
This comparison gets argued endlessly and it has a much simpler answer than most of the arguing suggests. It comes down to whether you already have usable ductwork. Everything else is a detail.
Run the two through the same pricing model and the reason is obvious:
| Situation | Central Air (3 ton) | Ductless (3 heads) | Winner |
|---|---|---|---|
| Usable ducts already there | $6,000 | $10,000 | Central air |
| No ducts at all | $13,500 | $10,000 | Ductless |
With ducts in place, central air wins by about $4,000, because you are only buying a condenser and a coil. With no ducts, ductless comes out about $3,500 ahead, so the price points the same way the practical argument does.
Owners who have done both keep landing on the same rule. One put it as: if you already have adequate ducts, adding a condenser and coil makes far more sense than a set of heads. Another pointed at the reason ductless wins the other case, which is that a house never built for ducts is genuinely hard to retrofit cleanly, and the soffits and boxed-in corners you end up with are a cost the quote does not show.
Tip: usable ducts means central air, no ducts means ductless, and the only case worth agonizing over is ducts that exist but need real work. In that middle case, price the duct repairs on the calculator above and compare against a mini split installation cost for the same rooms. Two things that legitimately override the price: wanting separate temperatures per room, which ductless does natively and central air needs zoning hardware for, and conditioning only part of the house, where paying to cool empty rooms makes no sense.
Window AC vs Central Air
A different question, because the money is not close. One owner facing a failed condenser laid the three options out: about $7,000 to replace the central system, $300 per unit for quiet window units, or roughly $1,000 per floor for ductless. Those are owner-reported figures, and the spread is the whole story.
What the price gap buys is not cooling, it is the things window units do not do: even temperatures without a box in every room, no reinstalling anything each spring, no blocked windows, and dehumidification across the whole house rather than one room at a time. The counterweight is repair exposure, and it is real. As one owner put it, when a window unit fails it is a $400 problem, not a $5,000 one. Tip: if the ducts are already there, central air is worth the money. If they are not, window units are a legitimate way to buy several more summers while you decide.