What size window AC for a bedroom?
A 10×12 bedroom (144 sq ft) needs about 3,600 BTU calculated — retail minimums are 5,000–6,000 BTU. A 9,000–10,000 BTU window unit is the practical sweet spot for comfort and dehumidifying.
Window AC Calculator
Window AC units are sold in fixed BTU steps — 5,000, 8,000, 10,000, 12,000 BTU and up. We calculate your load so you pick a unit that cools without short-cycling.
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Related guides
Frequently asked questions
Can a window AC be too big?
Yes. Oversized window units cool fast but leave humidity high. Match rated BTU to calculated load — do not buy the biggest unit that fits the opening.
Window AC vs mini-split BTU — same math?
Room load calculation is the same. Mini-splits are quieter and more efficient but cost more. Use the same BTU result when comparing types.
Related calculators
HVAC Calculators · https://hvaccalculators.net/window-ac-calculator/