What size AC do I need for a 1,500 square foot house?
A 1,500 square foot house typically takes a 2.5 to 3 ton air conditioner costing $6,000 to $8,500 installed, on HomeGuide's published home-size table.
That is a starting point rather than a specification, and HomeGuide says as much on the same page: professional load calculations account for square footage, insulation quality, window placement and efficiency, ceiling height and local climate. Two 1,500 square foot houses on the same street can need different equipment.
Source: HomeGuide
This page is general information, not professional advice. Prices move with your equipment, your region and the season, and the only number that counts is a written quote from a licensed HVAC contractor who has looked at your system.
How much is a new AC unit for a 1,500 sq ft house?
| Home size | Tons | Installed cost |
|---|---|---|
| 1,200 sq ft | 2 – 2.5 | $5,000 – $7,500 |
| 1,500 sq ft | 2.5 – 3 | $6,000 – $8,500 |
| 1,600 sq ft | 3 – 3.5 | $6,200 – $9,000 |
| 1,800 sq ft | 3 – 4 | $6,500 – $10,000 |
| 2,000 sq ft | 3.5 – 4.5 | $7,000 – $11,500 |
Source: HomeGuide
Cross-checked against the same guide's tonnage table, the numbers line up: a 2.5 ton system is $5,400 to $7,200 installed and a 3 ton is $5,800 to $7,800. Angi's national average across all house sizes is $5,977, with a range of $1,400 to $12,500.
The rule of thumb, and why it cannot size your system
HomeGuide gives the shortcut everybody quotes: about 16 to 30 BTU for each square foot, where one ton of cooling equals 12,000 BTU. Run it on 1,500 square feet and you get anywhere from 24,000 BTU to 45,000 BTU — 2 tons at one end and nearly 4 at the other. That spread is the whole problem with the rule of thumb.
Source: HomeGuide
The real instrument has a name. The Air Conditioning Contractors of America publishes Manual J, an ANSI-approved residential load calculation that gives the heating and cooling load for a specific house, along with Manual S for choosing equipment to match it and Manual D for designing the ducts. If a contractor names a tonnage without running one, that is the question to ask.
Getting it wrong costs money in both directions. HomeGuide puts it bluntly: an oversized unit will short-cycle and waste energy, while an undersized system runs constantly without adequately cooling the home. It also prices a professional load calculation as an added upfront cost that ensures proper sizing.
Source: HomeGuide
What moves the price on a 1,500 square foot house
Efficiency is the biggest single lever. HomeGuide's SEER table runs from $5,300 to $7,900 installed for a 13 to 14 SEER unit up to $11,400 to $17,300 for a 22 to 26 SEER one. It also notes the federal minimums: 14 SEER in northern and southwestern states and 15 SEER in southeastern regions.
Source: HomeGuide
- Climate. HomeGuide says southern regions often need higher-efficiency units because the warm season runs longer.
- Ductwork. HomeGuide prices minor duct sealing and repairs at $300 to $1,500, and a full replacement at $1,400 to $5,600. None of it is in the installed price above.
- Permits. HomeGuide prices a straight AC replacement permit at $100 to $250, and $250 to $1,500 when new ductwork is part of the job.
- Season. HomeGuide says late fall and early spring are off-season and contractors discount then, with May through August the peak.
How long the work takes
HomeGuide breaks it down by scope: 4 to 8 hours to replace the outdoor unit alone, 8 to 14 hours for both the outdoor and indoor units, and 2 to 3 days for a complete installation with ductwork changes. It says a new system lasts 15 to 20 years on average.
Source: HomeGuide
To run the same numbers against your own tonnage and repair quote: the HVAC replacement cost calculator.
HomeGuide's own advice is to compare quotes from at least three certified installers on the same size and the same efficiency. These are the HVAC companies AI assistants actually name when homeowners ask.
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Questions people ask next
- Is a 3 ton AC too big for 1,500 square feet?
- HomeGuide's home-size table gives 2.5 to 3 tons for a 1,500 square foot house, so 3 tons sits at the top of the published band rather than outside it. Whether it is right for your house is what a Manual J load calculation from the Air Conditioning Contractors of America answers.
- How many BTU do I need for 1,500 square feet?
- HomeGuide's rule of thumb of 16 to 30 BTU per square foot gives 24,000 to 45,000 BTU, and it says one ton equals 12,000 BTU. The spread is wide enough that the rule of thumb narrows the answer without settling it.
- Does the installed price include ductwork?
- No. HomeGuide footnotes every home-size and tonnage figure as excluding ductwork modifications or replacement, and prices those separately at $300 to $1,500 for sealing and repairs or $1,400 to $5,600 for a full replacement.
- What SEER rating should I buy for a house this size?
- HomeGuide publishes the federal minimums as 14 SEER in northern and southwestern states and 15 SEER in southeastern regions, and its price table shows what each step up costs. Higher SEER costs more upfront and less to run, so the answer depends on your climate and how long you are staying.
Written for homeowners by Most Recommended HVAC, which measures which HVAC companies AI assistants actually recommend in 26 U.S. metros. Nobody can pay to be on those lists. How we measure.