AC unit cost by size (tons)
Central air conditioner prices rise with size. A 2-ton unit costs about $5,000 to $6,800 installed, a 3-ton about $5,800 to $7,800, and a 5-ton about $7,000 to $9,500 or more for standard efficiency.
Quick answer
$4,700 – $9,5001.5 to 5 tons, standard efficiency installed
Most homes need 2 to 4 tons of cooling, costing $5,000 to $8,800 installed. A 1.5-ton unit starts near $4,700, and a 5-ton unit reaches $9,500+.
Prices by size
| Size | Capacity | Unit price | Installed | Home size (sq ft) |
|---|---|---|---|---|
| 1.5 tons | 18,000 BTU | $2,200 – $3,500 | $4,700 – $6,500 | 600 – 1,100 |
| 2 tons | 24,000 BTU | $2,500 – $3,800 | $5,000 – $6,800 | 900 – 1,400 |
| 2.5 tons | 30,000 BTU | $2,900 – $4,200 | $5,400 – $7,200 | 1,200 – 1,600 |
| 3 tons | 36,000 BTU | $3,300 – $4,800 | $5,800 – $7,800 | 1,500 – 2,100 |
| 3.5 tons | 42,000 BTU | $3,700 – $5,300 | $6,200 – $8,300 | 1,800 – 2,300 |
| 4 tons | 48,000 BTU | $4,000 – $5,800 | $6,500 – $8,800 | 2,100 – 2,700 |
| 5 tons | 60,000 BTU | $4,500 – $6,500 | $7,000 – $9,500 | 2,500 – 3,500 |
Square footage ranges are rough; climate, insulation, windows and ceiling height change the right size.
How to choose the right size
A common starting rule is about 20 BTU per square foot, or roughly 1 ton for every 500 to 600 square feet in a moderate climate. Hot, sunny homes need more; well-insulated homes need less. Use the AC size calculator, then ask your contractor for a Manual J load calculation.
Why bigger isn't better
An oversized AC cools quickly but shuts off before removing humidity, leaving the house clammy, and short cycling wears out the compressor. Undersized units run constantly on hot days. Correct sizing usually saves money on the unit and on bills.
Detailed guides by size
- 2-ton AC unit cost
- 2.5-ton AC unit cost
- 3-ton AC unit cost
- 3.5-ton AC unit cost
- 4-ton AC unit cost
- 5-ton AC unit cost
How to get a fair quote
- Get at least three written quotes that list the brand, model number, size (tons or BTU) and efficiency rating.
- Ask whether the price includes permits, removal of the old unit, refrigerant, a new thermostat and any duct or electrical work.
- Ask for a load calculation (Manual J) instead of matching the old unit's size by default.
- Compare labor warranties (1 to 10 years) as well as the manufacturer's parts warranty, and register the equipment.
- Schedule non-urgent work in spring or fall, when contractors are less busy and more willing to discount.
Frequently asked questions
How much does a 3-ton AC unit cost installed?
About $5,800 to $7,800 for a standard-efficiency 3-ton central air conditioner, including the matching coil and installation.
What size AC do I need for 2,000 square feet?
Often 3.5 to 4 tons, but it can range from 3 to 5 tons depending on climate, insulation and sun exposure.
How many square feet does a 5-ton AC cool?
Roughly 2,500 to 3,500 square feet in a moderate climate. Five tons is the largest size for most single residential units.
Sources
Prices are national averages and typical ranges from published cost data. Your price depends on your home, region, equipment and contractor, so get several written quotes. Heat & Air Costs is not an HVAC contractor; read our disclaimer.