Before buying an air conditioner, you have to make the AC tonnage calculation. Not sizing an AC unit properly can cause $100s in wasted unit costs or future electricity costs.
According to the DOE,
“…an air conditioner generally needs 20 BTU for each square foot of living space.”
We need to convert BTU to tonnage. 1 ton equals 12,000 BTU. That means that, on average, we will need 0.0016 tons per square foot.
To properly get the tonnage of the AC you need, you can use the AC tonnage calculator here:
For example, a standard 1,500 sq ft house would need a 2.5-ton air conditioner. To help us out, here is a quick table showing how many tons (and BTU) air conditioners we need for certain square footage:
|Area (Square Feet):||BTU||Tonnage|
|600 sq ft||12,000 BTU||1 Ton|
|900 sq ft||18,000 BTU||1.5 Tons|
|1,200 sq ft||24,000 BTU||2 Tons|
|1,500 sq ft||30,000 BTU||2.5 Tons|
|1,800 sq ft||36,000 BTU||3 Tons|
|2,100 sq ft||42,000 BTU||3.5 Tons|
|2,400 sq ft||48,000 BTU||4 Tons|
|2,700 sq ft||54,000 BTU||4.5 Tons|
|3,000 sq ft||60,000 BTU||5 Tons|
|3,300 sq ft||66,000 BTU||5.5 Tons|
|3,600 sq ft||72,000 BTU||6 Tons|
Example 1: 1.5 ton AC covers how many square feet?
Now you can answer this question. A 1.5 ton AC unit covers 900 square feet of living space.
Example 2: How many square feet does a 3-ton air conditioner cool?
How many square feet does a 3-ton air conditioner cover is quite easy to answer as well. 3-ton is equal to 36,000 BTU. If you apply the 20 BTU per sq ft rule of thumb, you can see that a 3-ton air conditioner cools about 1,800 square feet spaces.
Here is the most frequently asked question about tonnage, BTU, and area (square footage):
How Many Tons Of AC Per Square Foot? (Tonnage Per Square Foot)
Simple answer: You need 0.0016 tons of AC per square foot.
In short, if you’re looking to cool down a 600 sq ft area, you would need:
AC Capacity = 600 sq ft * 0.0016 tons/sq ft = 1 Ton
In general, for every 600 sq ft, you need 1 ton of AC. This is a general estimate.
You can use the ‘tonnage per square foot’ formula to calculate how many tons of AC you need. Here is the formula:
AC Capacity (Tonnage) = (INSERT AREA IN SQ FT) * 0.0016 tons/sq ft
You can insert the area and calculate how many tons of AC you need per certain square footage.
When you calculate the tonnage, you can check out several 1-4 ton mini-split air conditioners here:
- Single Zone Mini Split ACs: 1 Ton or 12,000 BTU. Estimated square footage: 600 sq ft.
- Dual Zone Mini Split ACs: About 2 Tons or 24,000 BTU. Estimated square footage: 1,200 sq ft.
- 3-Zone Mini Split ACs: About 3 Tons or 36,000 BTU. Estimated square footage: 1,800 sq ft.
- 4-Zone Mini Split ACs: About 3 Tons or 36,000 BTU. Estimated square footage: 1,800 sq ft.
- 5-Zone Mini Split ACs: About 4 Tons or 48,000 BTU. Estimated square footage: 2,400 sq ft.
Hope this helps. If you have any questions, you can pose them in the comments below.