Find the minimum BTU rating your air conditioner needs based on your exact room size, sun exposure, and occupancy.
The same room-volume-and-ceiling-height math applies to sizing an air purifier, too — if you want a more in-depth explanation of how that works, see our guide on how to choose the right size air purifier.
ft long
ft wide
ft high
people
Add 600 BTU for each person beyond 2 regularly using the room.
Minimum BTU you need
7,200BTU
Achievable with a standard window AC
Floor area
144 sq ft
Base BTU
2,880
Adjustments
+0
Real air conditioners that clear this BTU
Formula: base BTU comes from the standard room-size sizing table (100 sq ft ≈ 5,000 BTU up to 2,500 sq ft ≈ 34,000 BTU), scaled for
Ceiling Height ÷ 8, then ±10% for sun exposure, +600 BTU per occupant beyond 2, and +4,000 BTU if the room is a kitchen. This mirrors the sizing guidance most AC manufacturers and energy-efficiency guides publish.
