What does this tool do?
Room BTU is estimated from floor area, ceiling height and how well the space is insulated. This calculator applies a base rate of 20 BTU per sq ft for cooling or 35 BTU per sq ft for heating, then converts to kilowatts.
The Formula
BTU = Floor area × Base BTU per sq ft × (Ceiling height ÷ 8) × Insulation factorFrequently Asked Questions
How many BTU per square foot?
About 20 BTU per sq ft for cooling and 35 BTU per sq ft for heating in a typical insulated room with 8 ft ceilings.
Is this the same as air conditioner tonnage?
One ton equals 12,000 BTU per hour, so divide the cooling BTU by 12,000 to compare with equipment sizes.