What Size AC Do I Need for 250 Square Feet?

Answer
6,000 BTU/h for 250 sq ft

By the Energy Star room AC sizing chart, a 250 ft² room needs about 6,000 BTU/h (1.76 kW, 0.50 ton). Make it 7,000 BTU if the room is very sunny or 6,000 BTU if it is heavily shaded; add 600 BTU per person above two and 4,000 BTU for a kitchen.

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Recommended AC capacity
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How we calculated this

    For estimating and educational purposes only. Results are approximate and are not a substitute for a licensed professional, the manufacturer's instructions or your local code. Disclaimer

    AC size for a 250 sq ft room

    SituationBTU/h
    Average room, 2 people6,000
    Very sunny (+10%)7,000
    Heavily shaded (−10%)6,000
    4 people8,000
    Kitchen (+4,000 BTU)10,000
    Poor insulation / top floor8,000

    Rule-of-thumb sizing for single rooms with 8 ft ceilings. Window units come in 5,000–24,000 BTU; mini-splits in 9,000–36,000 BTU.

    Frequently asked questions

    Is 6,000 BTU enough for 250 sq ft with a kitchen?

    Not quite: add 4,000 BTU for the kitchen, so about 10,000 BTU.

    How many tons is 6,000 BTU?

    0.50 ton. One ton of cooling is 12,000 BTU/h.

    Open the full calculator: AC BTU Calculator: What Size Air Conditioner Do I Need? →