🌡️ Air Conditioner BTU Calculator
Calculate how many BTUs of cooling capacity you need for a room based on its size and other factors.
What this calculator does
This tool estimates the BTU (British Thermal Unit) cooling capacity needed for a room, factoring in floor area, sun exposure, number of occupants, and whether the room is a kitchen (which generates extra heat).
The formula
The base estimate is about 20 BTU per square foot, adjusted by a sun exposure multiplier. An additional 600 BTU is added for each occupant beyond two people, and 4,000 BTU is added if the room is a kitchen, following common room air conditioner sizing guidelines.
This is a general guideline for sizing a single-room or window/portable air conditioner. For whole-home central AC systems, a professional Manual J load calculation is recommended.