How is the BTU figure calculated?

It starts from about 20 BTU per square foot of floor area, then adjusts up to 10% for sun exposure and adds roughly 600 BTU for each occupant beyond two. The total is rounded up to the nearest 100.

Is this a substitute for a professional load calculation?

No. It is a quick sizing guide for a single room. Ceiling height, insulation, climate and appliances all affect real cooling load, so confirm with an installer for a permanent system.

Is anything uploaded?

No — every calculation happens in your browser and nothing is sent to a server.

BTU Air Conditioner Calculator

BTU air conditioner calculator — size your unit

A BTU calculator estimates the cooling capacity an air conditioner needs for a room. Enter the room size, pick the sun exposure, and set how many occupants the room usually has. The tool returns a recommended capacity in BTU per hour.

The estimate starts from the common rule of about 20 BTU per square foot and adjusts for heat gain — a useful starting point for choosing a unit. It all runs in your browser with nothing uploaded.