BTU Calculator (Air Conditioner Size)
BTU calculator: the air conditioner size (BTU/h) a room needs from its area, sun exposure, occupants and kitchen use.
BTU/h ≈ 20 × ft² × adjustments
How to use this calculator
- Type your input in the box.
- The result updates as you type.
- Use “Copy result” or “Copy link” to share it.
Energy Star guideline: about 20 BTU per ft², +10 % for very sunny rooms, −10 % for shady ones, +600 BTU per extra person over two, +4,000 for a kitchen.
Frequently asked questions
350 ft² room, normal sun, two people?
About 7,000 BTU/h (2.05 kW).
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