BTU Calculator
Answer a few questions about your room and we will recommend the right air conditioner size. Getting the BTU right means efficient cooling without wasted energy.
Your Recommendation
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Recommended BTU
Now that you know your BTU, browse our guides to find the right unit:
- Window AC (5,000–14,000 BTU)
- Portable AC (8,000–14,000 BTU)
- Mini-Split (9,000–36,000 BTU)
- Central HVAC (24,000+ BTU)
How BTU Is Calculated
BTU (British Thermal Unit) measures cooling capacity. The base calculation is 20 BTU per square foot, then adjusted for ceiling height, sun exposure, climate, occupancy, and room usage. An oversized unit cools quickly but short-cycles, leaving excess humidity. An undersized unit runs continuously without reaching the desired temperature.
Quick Reference Table
| Room Size | BTU (standard conditions) |
|---|---|
| 100–150 sq ft | 5,000 |
| 150–250 sq ft | 6,000 |
| 250–350 sq ft | 8,000 |
| 350–450 sq ft | 10,000 |
| 450–550 sq ft | 12,000 |
| 550–700 sq ft | 14,000 |
| 700–1,000 sq ft | 18,000 |
| 1,000–1,200 sq ft | 21,000 |
| 1,200–1,500 sq ft | 24,000 |