Cooling · Room sizing
What size AC for a 1,200 sq ft room?
A 1,200 sq ft room with 8 ft ceilings needs about 135,921 BTU/h (11.3 tons) of cooling in a hot climate — buy a 60,000 BTU unit, or 60,000 BTU if the room gets direct sun.
By ceiling height
| Ceiling | BTU/h (shaded) | BTU/h (sunny) | Tons |
|---|---|---|---|
| 8 ft | 135,921 | 163,105 | 11.3 |
| 9 ft | 152,911 | 183,493 | 12.7 |
| 10 ft | 169,901 | 203,881 | 14.2 |
Hot-climate volumetric method (500–600 BTU/h per m³) — the same formula as our BTU calculator, where you can enter exact dimensions. In mild climates use the room-size chart's 20–25 BTU/sq ft column instead.
FAQ
- How many BTU for 1,200 sq ft?
- In a hot climate with 8 ft ceilings: about 135,921 BTU/h shaded, or 163,105 BTU/h with direct sun. In a mild climate the 20–25 BTU/sq ft rule gives 24,000–30,000 BTU/h — use that as the floor for insulated rooms.
- How many tons is that?
- 135,921 BTU/h equals 11.3 tons of cooling (1 ton = 12,000 BTU/h) — about 39.9 kW.
Other sizes: 1,000 sq ft · 1,500 sq ft · any size