BTU Needed for a Room
Enter a room's square footage and a few adjustments to estimate how much cooling capacity (BTU/h) it needs. This is an estimate, not a substitute for a professional load calculation.
Estimated cooling capacity needed
5000 BTU/h
≈ 1.4654 kW · ≈ 0.416667 tons of refrigeration
This is a rough estimate based on a common rule-of-thumb (20 BTU/h per square foot, adjusted for climate, sun exposure, and occupancy). It does not account for insulation quality, ceiling height, window area, or appliance heat load. For an exact sizing, use a Manual J load calculation or consult an HVAC professional.
How this estimate works
We start from a baseline of 20 BTU/h per square foot, then adjust for climate (cool, mild, warm, or hot), sun exposure (shaded, average, or sunny), and occupancy — adding roughly 600 BTU/h for each occupant beyond two, since bodies generate heat.
Need to convert between HVAC power units directly? See the HVAC converters, including tons to BTU/h and kW to BTU/h.