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Sizing
What Size Air Conditioner Do I Need?
September 6, 2026 3 min read
Residential air conditioners are commonly sized from 1.5 to 5 tons. Square footage gives you a planning range, but a Manual J load calculation gives you the final answer.
A practical planning range
| Home size | Common planning range |
|---|---|
| Up to 1,200 sq. ft. | 1.5–2 tons |
| 1,200–1,800 sq. ft. | 2–3 tons |
| 1,800–2,500 sq. ft. | 3–4 tons |
| 2,500–3,200+ sq. ft. | 4–5 tons |
Climate, insulation, windows, ceiling height, shade, and leakage can move a home outside these broad ranges.
Bigger is not safer
An oversized system cools quickly but may shut off before removing enough humidity. An undersized system can struggle on design days. Proper sizing balances temperature, humidity, run time, and airflow.
What a professional verifies
- Manual J cooling load
- Duct capacity and static pressure
- Indoor and outdoor equipment match
- Electrical requirements
- Refrigerant line size and condition