AC size for a 1,500 sq ft room
30,000 BTU
for a 1,500 sq ft room (2.5 tons) · about 2,500 W at EER 12
Adjust for the room
| Condition | BTU/h |
|---|---|
| Normal room | 30,000 |
| Very sunny (+10%) | 33,000 |
| Shaded (−10%) | 27,000 |
| Kitchen (+4,000) | 34,000 |
| 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 | 300 kWh | $51 |
| 8 h/day | 600 kWh | $102 |
| 12 h/day | 900 kWh | $153 |
FAQ
What size AC for 1,500 square feet?
About 30,000 BTU (2.5 tons); add 10% for a sunny room and 4,000 BTU for a kitchen.
How much does it cost to run a 30,000 BTU AC?
At roughly 2,500 W, 8 hours a day for a month uses 600 kWh, about $102 at $0.17/kWh.