AC Unit Cost by Size (2026): 2, 3, 4 & 5 Ton Prices

Air conditioners are sized in tons. One ton moves 12,000 BTUs of heat per hour. Bigger units cost more, but the jump from size to size is smaller than most people expect.

Price by tonnage

Size	BTU	Unit (HomeGuide)	Installed (HomeGuide)	Average cost (Angi)
1.5 ton	18,000	$2,200 – $3,500	$4,700 – $6,500	$1,300 – $4,000
2 ton	24,000	$2,500 – $3,800	$5,000 – $6,800	$1,500 – $5,000
2.5 ton	30,000	$2,900 – $4,200	$5,400 – $7,200	–
3 ton	36,000	$3,300 – $4,800	$5,800 – $7,800	$2,000 – $5,500
3.5 ton	42,000	$3,700 – $5,300	$6,200 – $8,300	–
4 ton	48,000	$4,000 – $5,800	$6,500 – $8,800	$2,600 – $6,200
5 ton	60,000	$4,500 – $6,500	$7,000 – $9,500+	$2,800 – $6,800

HomeGuide's installed prices are for a basic installation without ductwork changes. Angi's ranges run lower, so get local quotes.

Equipment only

Angi's HVAC replacement guide lists equipment, without labor, at about $2,000 for 1.5 tons, $2,900 for 2.5 tons, $3,000 for 3 tons and $3,500 for 3.5 tons.

What size do you need?

Home size	Typical size (HomeGuide)
1,000 sq ft	1.5 – 2 tons
1,500 sq ft	2.5 – 3 tons
2,000 sq ft	3.5 – 4.5 tons
2,500 sq ft	4.5 – 5 tons
3,000 sq ft	5+ tons

These are rough guides. Angi notes that climate, insulation, home age and windows all change the right size. A contractor should run a load calculation (Manual J). An oversized unit cycles on and off too often and leaves the house clammy; an undersized one runs constantly on hot days.

Installed cost by home size

Home size	Installed (HomeGuide)
1,200 sq ft	$5,000 – $7,500
1,600 sq ft	$6,200 – $9,000
1,800 sq ft	$6,500 – $10,000
2,200 sq ft	$7,800 – $12,500

Efficiency changes the price more than size

On HomeGuide's figures, moving from a 3-ton to a 4-ton unit adds about $700 to $1,000 installed, while moving from 13–14 SEER ($5,300 – $7,900) to 17–18 SEER ($7,500 – $10,600) adds over $2,000. See AC replacement cost for prices by SEER.

Replacing only part of the system

If the unit is the right size and only one part failed, compare AC compressor replacement cost before buying a whole system.

How AC size is measured

Central air conditioners are sized in tons of cooling capacity. One ton equals 12,000 BTUs per hour of heat removal. Residential systems commonly range from about 1.5 to 5 tons.

Why a load calculation matters

The right size depends on far more than square footage: insulation, window area and direction, ceiling height, air leakage, ductwork, local climate and the number of people in the home. Contractors use a Manual J load calculation to size the system properly. Rules of thumb based only on square footage often lead to the wrong size.

Problems with the wrong size

Oversized: short cycles, poor humidity control, uneven temperatures, more wear.
Undersized: runs constantly on hot days and cannot keep the house cool.

Size and price

Larger units cost more, but the difference between sizes is usually smaller than the difference between efficiency levels and brands. Choosing the correct size is about comfort and efficiency, not saving money on a smaller unit.

Other factors that change the price

Efficiency rating (SEER2).
Single-stage, two-stage or variable-speed compressors.
Matching indoor coil and air handler.
Ductwork that may need resizing to handle the airflow of a different system.

Questions to ask

Will you do a Manual J load calculation?
Is my ductwork sized correctly for the new system?
Would a variable-speed system help with humidity in my home?

In Texas

Hot summers and, in many areas, high humidity make sizing especially important in Texas. An oversized system in a humid climate like Houston's can leave the home cool but clammy, because it does not run long enough to remove moisture.

How to estimate size before getting quotes

AC capacity is measured in tons, where one ton equals 12,000 BTUs per hour of cooling. Rules of thumb, like a set number of square feet per ton, are only rough starting points. The real answer comes from a load calculation, often called Manual J, which considers:

Square footage and ceiling height.
Insulation levels in the walls and attic.
Window size, type and direction.
Air leakage and ductwork location.
The local climate.
The number of people in the home and heat from appliances.

Two homes of the same size can need different-sized systems because of these factors.

Why bigger is not better

An oversized AC cools the air quickly and then shuts off before it removes much humidity. The result can be a cold, clammy house, more temperature swings and more wear from frequent starting and stopping. An undersized AC runs constantly on hot days and may not keep up. The right size balances comfort, efficiency and equipment life.

Size and ductwork

The ductwork must be able to carry the airflow the new system needs. Upsizing an AC without checking the ducts can lead to noisy vents, poor airflow and lower efficiency. If you are increasing capacity, ask the installer whether the ducts can handle it.

Replacing an oversized system

If your current system seems too large, such as short cycling and poor humidity control, replacement is a chance to right-size it. A load calculation may show you need a smaller system, which can cost less and work better.

Questions to ask about sizing

Did you perform a load calculation, and can I see the results?
Why did you choose this size?
Will the existing ductwork support it?
How will this system control humidity in my home?

Size and efficiency together

The final price depends on both size and efficiency. A larger unit at a basic efficiency level can cost less than a smaller unit at a high efficiency level. When comparing quotes, compare units of the same size and efficiency so the prices line up.

Matching the indoor and outdoor parts

When the AC size changes, the indoor coil and often the furnace blower must be able to support the new capacity. A larger outdoor unit paired with a small coil or a weak blower will not deliver the cooling you paid for. Installers check the coil and blower ratings for this reason. If your furnace is old, ask whether its blower can handle the new size, or whether replacing both parts at once makes more sense.

City	Businesses listed	Avg. Google rating	Total reviews
Houston	464	4.7	72,003
Dallas	121	4.8	26,510
San Antonio	200	4.7	63,399
Austin	108	4.8	39,568
Fort Worth	99	4.7	25,658
El Paso	66	4.5	11,208

AC Unit Cost by Size (Tons)