Formula
Tons = BTU/hr ÷ 12,000 · Rough: sqft × zone factor × constructionSquare-footage sizing is a rough starting point. For final sizing always run Manual J with actual window area, orientation, infiltration, and internal gains.
Cooling load
50,400BTU/hr
50.4 kBTU/hr · 14.77 kW
Nominal size
4.20tons
Round to nearest 0.5 ton for equipment selection
Reference: 1 ton = 12,000 BTU/hr = 3.517 kW. Typical residential: 400–500 sqft/ton depending on climate and envelope.