FREE TOOL · NO ACCOUNT NEEDED
BTU Calculator
Estimate room air-conditioner cooling capacity from floor area and room use.
Your estimate
Enter measurements and select Calculate.
How this estimate works
Room-cooling estimate for an 8 ft ceiling and 100–2,500 FT² floor area. Uses ENERGY STAR’s sizing table; shaded rooms reduce the table capacity by 10%, sunny rooms increase it by 10%, occupants beyond two add 600 BTU/h each, and kitchens add 4,000 BTU/h. Exact shared table boundaries use the higher band. This is not heating sizing or a whole-building HVAC load calculation.
ENERGY STAR room air-conditioner sizing guidance
Values are rounded only for display. Calculations stay on this device. No signup required.
← All calculators