Find the right air conditioner size for your room.
How this worksStart with a base of 20 BTU per square foot. Sunny rooms get +10%, shaded rooms get −10%. Ceilings over 8 feet add 10% per extra foot (more air to cool), and kitchens add 4,000 BTU for appliance heat. The result is rounded to the nearest 500 BTU to match standard AC sizes. An oversized unit cools fast but cycles off before dehumidifying — closer to the right size is better.