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, and that's the safest default.
One thing worth clearing up before you read the numbers, because it confuses a lot of people. A whole house and a single room of the same square footage do not need the same tonnage, and a house usually needs less per square foot than one big open room does. The reason is that a house is chopped up by interior walls, only some rooms are in use at once, and the load gets spread across the whole envelope instead of hitting one space. A single 1,000 sq ft open room with afternoon sun and people in it is a much harder job than a 1,000 sq ft house with three bedrooms. So if you are sizing one room rather than a house, use our AC tonnage calculator instead, which works from room dimensions.
| 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 |
The table gives you the range. Below we have gone through each size one at a time, because the range is wide and where you land inside it is the whole question. And a warning before you read them: the ranges assume the ductwork can actually carry the air. An older home built for a smaller system may have ducts sized for only 600 to 800 CFM, which is not enough for 2.5 tons no matter what the square footage says. If you are stepping up a size, get the ducts checked with our duct size calculator before you buy.
1.5 Ton AC Unit Square Footage
A 1.5 ton unit covers roughly 600 to 950 sq ft. That is a small house, a large apartment, or a finished basement. Take the low end in the South and the high end up north. Below about 600 sq ft you are into single-room territory, and at that point a ductless head usually makes more sense than a whole central system.
2 Ton AC Unit Square Footage
Two tons handles roughly 900 to 1,300 sq ft. This is the size people most often discover they have and then start doubting, so it is worth being clear about where the line falls.
Homeowners report a 2 ton system running a 1,150 sq ft house in South Carolina without complaint. The same 2 tons in a 2,350 sq ft house had the unit running all day and never catching up, and in a 1,650 sq ft house an installer called it undersized outright. So if your house is over about 1,300 sq ft and the AC runs constantly on hot afternoons, the size is the first thing to check, not the refrigerant.
2.5 Ton AC Unit Square Footage
At 2.5 tons you are looking at about 1,150 to 1,600 sq ft. It is the usual answer for a mid-size single-storey home, and it is also the step where ductwork starts to matter more than tonnage. A house built for 2 tons will not automatically move the extra air, so if you are upgrading rather than replacing like for like, that is the moment to have the duct sizing looked at.
3 Ton AC Unit Square Footage
A 3 ton unit covers roughly 1,400 to 1,900 sq ft, and this is the most common central AC size in American homes.
But the spread inside that range is real. One owner reports 3 tons cooling 1,400 sq ft comfortably. Another with an 1,844 sq ft house on the same 3 tons said it could not keep up once the outside temperature passed 90°F, while holding the house at 70°F. Both are inside the range. The difference is not the square footage, it is how hard you are asking the system to work and how well the house holds heat out. If you are at the top of the range in a hot climate and you like the house cold, size up.
3.5 Ton AC Unit Square Footage
Three and a half tons stretches from about 1,650 to 2,250 sq ft. This size does not exist in every product line, which is why some quotes jump straight from 3 to 4 tons. It is worth asking for, because the jump from 3 to 4 is a big one to make on a house sitting in the middle. An older ranch of about 1,465 sq ft with poor insulation was sized at 3.5 tons by its installer, which is well above what the square footage alone suggests, and that is the envelope doing the talking rather than the floor plan.
4 Ton AC Unit Square Footage
Four tons takes you from about 1,900 to 2,600 sq ft. At this size a single system is usually still fine for a one-storey home, but a two-storey house of the same footage often does better with zoning or a second system, because the upstairs will always run warmer than the downstairs no matter how much capacity you buy.
5 Ton AC Unit Square Footage
A 5 ton unit covers roughly 2,400 to 3,300 sq ft, and it is the largest standard residential size. Above this you are not buying a bigger unit, you are buying a second system, because residential equipment stops at 5 tons. So if a contractor quotes you a single unit for a 3,500 sq ft house in a hot climate, ask them to show you the load calculation, because the answer is usually two systems. Our HVAC load calculator gives you the whole-house number to check that against.
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 tons in most of the US, rising to 2.5 tons in hot, humid states and dropping to as little as 1.5 tons up north. That's 18,000–30,000 BTU/hr.
What Size AC Unit for 1200 Square Feet?
A 1,200 sq ft house needs about 2 to 2.5 tons in a moderate climate, 2.5 to 3 tons in the hot South, and 2 tons in cold northern states. This is the size where a 2 ton unit stops being a safe default, so if yours is 2 tons and struggling on hot afternoons, it is probably genuinely undersized rather than faulty.
What Size AC Unit for 1300 Square Feet?
For 1,300 sq ft, plan on 2.5 tons in a moderate climate, 3 tons in hot and humid states, and 2 tons up north. You are inside the 2.5 ton coverage band here with a little room to spare, which makes this one of the easier sizes to get right.
What Size AC Unit for 1400 Square Feet?
A 1,400 sq ft home lands on 2.5 to 3 tons, going to 3 tons in the South and 2 to 2.5 tons in cold climates. Owners report 3 tons cooling 1,400 sq ft comfortably, so if your quote says 2.5 and the house is in a hot state, ask what the load calculation actually returned before you accept the smaller size.
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.
What Size AC Unit for 1600 Square Feet?
For 1,600 sq ft, plan on 3 tons in a moderate climate, 3.5 tons in the hot South, and 2.5 tons in cold states. An installer looking at a 1,650 sq ft house on 2 tons called it undersized outright, which is worth knowing if you inherited a system with the house.
What Size AC Unit for 1700 Square Feet?
A 1,700 sq ft home needs about 3 to 3.5 tons, closer to 3.5 or 4 in Texas and Florida, and 2.5 to 3 tons in northern states. This is where the 3.5 ton size earns its place, because the jump from 3 straight to 4 tons is a big one for a house sitting in the middle.
AC Tonnage for an 1,800 Sq Ft House
An 1,800 sq ft home typically needs 3 to 3.5 tons, or 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 tons in 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.
What Size AC Unit for 2200 Square Feet?
A 2,200 sq ft house needs about 4 tons in a moderate climate, 5 tons in the hot South, and 3 to 3.5 tons in cold states. At this size a two-storey layout matters more than the square footage does, because the upstairs will run warmer whatever capacity you buy, and zoning usually solves that better than a bigger unit.
AC Tonnage for a 2,500 Sq Ft House
A 2,500 sq ft house needs about 4.5 tons in 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 tons in 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 ft instead 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 Tonnage Calculator AC 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. And once you've settled on a tonnage, see what it costs installed with the central AC installation cost calculator.