Capacity check
BTU per Square Foot Calculator
Calculate a capacity-to-area ratio from a rated BTU/h value and measured floor area.
Calculate BTU/h per ft²
This is a ratio, not a complete load calculation.
Formula
BTU/h per ft² = rated BTU/h ÷ floor area (ft²)
Variables
Use the nameplate or published capacity and the actual conditioned floor area.
Example
12,000 BTU/h over 500 ft² equals 24 BTU/h per ft².
FAQ
Does this tell me what size system to buy?
No. It only reports a ratio. Actual loads depend on construction, climate, solar gain, occupants, and ventilation.