AC Tonnage Chart by Square Footage
This chart shows the typical central AC tonnage for a whole house with average insulation and standard 8 ft ceilings. Find your home's square footage on the left, then use the column that matches your climate. If you fall between two sizes, hot climates round up and cold climates round down — that's the safest default.
| Home Size (sq ft) | Hot Climate (South) | Moderate Climate (Mid-US) | Cold Climate (North) |
|---|---|---|---|
| 600 | 1.5 tons | 1 – 1.5 tons | 1 ton |
| 800 | 2 tons | 1.5 tons | 1 – 1.5 tons |
| 1,000 | 2 – 2.5 tons | 2 tons | 1.5 tons |
| 1,200 | 2.5 – 3 tons | 2 – 2.5 tons | 2 tons |
| 1,500 | 3 – 3.5 tons | 2.5 – 3 tons | 2 – 2.5 tons |
| 1,800 | 4 tons | 3 – 3.5 tons | 2.5 – 3 tons |
| 2,000 | 4 – 4.5 tons | 3.5 tons | 3 tons |
| 2,200 | 5 tons | 4 tons | 3 – 3.5 tons |
| 2,500 | 5+ tons* | 4.5 tons | 3.5 – 4 tons |
| 3,000 | Two systems* | 5 tons | 4 – 4.5 tons |
| 3,500 | Two systems* | 5+ tons* | 5 tons |
*Residential central AC tops out at 5 tons per system. Beyond that, contractors typically install two smaller systems (often one per floor), which zones better and runs cheaper than one giant unit.
How Many Square Feet Does 1 Ton of AC Cover?
Flipping the question around: 1 ton of AC covers roughly 400 to 650 square feet, depending on your climate and insulation. In Miami or Houston, plan on the low end of that range. In Minneapolis, the high end. (Working from a BTU rating instead? First convert BTU to tons, then read the coverage off this table.) Here's the coverage for every standard size:
| AC Size | Coverage (sq ft) |
|---|---|
| 1 ton | 400 – 650 |
| 1.5 tons | 600 – 950 |
| 2 tons | 900 – 1,300 |
| 2.5 tons | 1,150 – 1,600 |
| 3 tons | 1,400 – 1,900 |
| 3.5 tons | 1,650 – 2,250 |
| 4 tons | 1,900 – 2,600 |
| 5 tons | 2,400 – 3,300 |
What Size AC Do I Need for My House?
These are the home sizes people ask about most. All numbers assume a whole house with average insulation — if yours is a 1970s home with original windows, nudge up half a ton; a tight new build, nudge down.
AC Tonnage for a 1,000 Sq Ft House
A 1,000 sq ft house needs about 2 tonsin most of the US — 2.5 tons in hot, humid states and as little as 1.5 tons up north. That's 18,000–30,000 BTU/hr.
AC Tonnage for a 1,500 Sq Ft House
For 1,500 sq ft, plan on 2.5 to 3 tons in a moderate climate, 3 to 3.5 tons in the South, and 2 to 2.5 tons in cold states. This is the single most common house-size question we see, and the honest answer is that 1,500 sq ft sits right on the line between 2.5 and 3 tons — which is exactly why climate and insulation matter so much here.
AC Tonnage for an 1,800 Sq Ft House
An 1,800 sq ft home typically needs 3 to 3.5 tons — about 4 tons in Texas or Florida heat, closer to 3 tons in mild or northern climates.
AC Tonnage for a 2,000 Sq Ft House
For 2,000 sq ft, the standard answer is 3.5 tonsin a moderate climate. Hot and humid regions push it to 4–4.5 tons, while cold-climate homes usually do fine with 3. Two-story homes often land at the lower end because the upstairs and downstairs share walls with each other instead of the outdoors.
AC Tonnage for a 2,500 Sq Ft House
A 2,500 sq ft house needs about 4.5 tonsin moderate climates and 3.5–4 tons in cold ones. In the hot South you're at the 5 ton ceiling — and at 2,600+ sq ft down there, many contractors will already suggest splitting into two systems.
AC Tonnage for a 3,000 Sq Ft House
At 3,000 sq ft you need roughly 5 tonsin a moderate climate and 4–4.5 tons in cold states. In hot climates, the math says more than 5 tons — which in practice means two systems, not one bigger unit, since residential equipment stops at 5 tons.
AC Tonnage Per Square Foot in Texas (and Other Hot States)
Texas deserves its own mention because it's the most common "does the rule of thumb still apply?" state. It mostly does, just shifted: in the Dallas–Houston–San Antonio triangle, figure 1 ton per 450–500 sq ftinstead of the national 500–600. Gulf Coast humidity adds latent load (moisture your AC has to wring out of the air before it can cool), and West Texas sun exposure does something similar through sheer heat. Florida, Louisiana, southern Arizona, and Georgia follow the same logic. If you're in any of these states, use the "Hot" column of the chart and don't be surprised when the answer looks half a ton bigger than what a national average would say.
Why Square Footage Is Only the Starting Point
Square footage gets you the right neighborhood, not the exact address. Two 2,000 sq ft homes can genuinely need ACs a full ton apart. The factors that move the number: ceiling height (10 ft ceilings hold ~25% more air than 8 ft), insulation era, window area and direction, how many people live there, and whether the ductwork runs through a 130°F attic. Professional contractors capture all of this with a Manual J load calculation — and our calculators are built to approximate the variables that matter most from that method.
So use this page the way contractors use rules of thumb: to sanity-check quotes and get in the right range. If a salesperson quotes 5 tons for your 1,500 sq ft house in Ohio, this chart is how you know to get a second opinion. For a proper estimate, run your home through the AC Tonnage Calculator room by room — and if you're checking what size your current unit is before replacing it, our tonnage-by-model-number decoder reads it straight off the data plate. The exact BTU-per-square-foot values and insulation factors this calculator uses are published in our methodology.