AC size for a 1,400 sq ft room
28,000 BTU
for a 1,400 sq ft room (2.3 tons) · about 2,333 W at EER 12
Adjust for the room
| Condition | BTU/h |
|---|---|
| Normal room | 28,000 |
| Very sunny (+10%) | 30,800 |
| Shaded (−10%) | 25,200 |
| Kitchen (+4,000) | 32,000 |
| Each extra person over 2 (+600) | +600 |
Rule of thumb: 20 BTU per sq ft with 8 ft ceilings (ENERGY STAR sizing guidance).
Monthly running cost at $0.17/kWh
| Use | Energy | Cost |
|---|---|---|
| 4 h/day | 280 kWh | $48 |
| 8 h/day | 560 kWh | $95 |
| 12 h/day | 840 kWh | $143 |
FAQ
What size AC for 1,400 square feet?
About 28,000 BTU (2.3 tons); add 10% for a sunny room and 4,000 BTU for a kitchen.
How much does it cost to run a 28,000 BTU AC?
At roughly 2,333 W, 8 hours a day for a month uses 560 kWh, about $95 at $0.17/kWh.