BTU Sizing Calculator
Find the right size mini split for a room or zone. Results update as you type.
Quick reference
| Room size | Typical capacity | Nominal size |
|---|---|---|
| Up to 300 sq ft | 6,000–9,000 BTU | ½–¾ ton |
| 300–550 sq ft | 12,000 BTU | 1 ton |
| 550–800 sq ft | 18,000 BTU | 1.5 ton |
| 800–1,100 sq ft | 24,000 BTU | 2 ton |
| 1,100–1,600 sq ft | 36,000 BTU | 3 ton |
| 1,600–2,200 sq ft | 48,000 BTU | 4 ton |
| 2,200–2,800 sq ft | 60,000 BTU | 5 ton |
Tip: an inverter mini split modulates its output, so going one size up is usually safer than one size down — but a unit that is far too large will short-cycle and dehumidify poorly.