What Size Air Conditioner Do I Need for 600 Sq Ft?
600 sq ft is in the middle of the 14,000 BTU/hr band, not on either edge.
Full breakdown: BTU per square foot.
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Capacity from the chart
| Area to be cooled | Capacity needed | Source |
|---|---|---|
| 550 up to 700 sq ft | 14,000 BTU/hr | ENERGY STAR |
The useful check at 600 sq ft is how much area you would have to gain or lose before the row changes. You would have to fall to 550 sq ft to touch the 12,000 band, or reach 700 sq ft to touch the 18,000 band. A sun adjustment cannot stand in for those square feet. Ten percent of 14,000 is 1,400 BTU/hr, so the sunny target is 15,400 and the shaded target is 12,600.
How to size it
Keep the floor area on the 14,000 row and layer only the adjustments that describe this space. People and kitchen use are additions. Shade and sun are a single percent in one direction.
| Adjustment | On the 14,000 row | Source |
|---|---|---|
| Heavily shaded, reduce capacity 10% | 14,000 − 10% = 12,600 BTU/hr | ENERGY STAR |
| Very sunny, increase capacity 10% | 14,000 + 10% = 15,400 BTU/hr | ENERGY STAR |
| Each additional person beyond two | 14,000 + 600 BTU/hr = 14,600 BTU/hr | ENERGY STAR |
| Unit used in a kitchen | 14,000 + 4,000 BTU/hr = 18,000 BTU/hr | ENERGY STAR |
10% of 14,000 BTU/hr is 1,400 BTU/hr (14,000 × 10%).
One person beyond two: 14,000 + 600 = 14,600 BTU/hr. Kitchen use: 14,000 + 4,000 = 18,000 BTU/hr. That 18,000 is the kitchen math, and it happens to equal the capacity ENERGY STAR prints for 700 up to 1,000 sq ft. Do not describe a 600 sq ft kitchen as if it had changed rows. If the kitchen is also very sunny, add the percent first: 14,000 + 10% = 15,400, then 4,000, for 19,400 BTU/hr.
The 14,000 figure is tied to an 8-foot ceiling. ENERGY STAR's note for anything taller is to select a room air conditioner with a higher CADR. It does not say to step up to 18,000 automatically.
14,000 BTU window air conditioners on Amazon Window air conditioner support brackets on Amazon
Related questions
- What size air conditioner for a 500 sq ft room
- What size air conditioner for 700 sq ft
- What size air conditioner for 800 sq ft
All of these questions are listed on the topic map.
Sources
- ENERGY STAR, Room Air Conditioners — https://www.energystar.gov/products/room_air_conditioners — accessed Oct 2, 2026.
Frequently asked questions
What size air conditioner do I need for 600 sq ft?
ENERGY STAR lists 550 up to 700 sq ft at 14,000 BTU/hr. 600 sq ft is inside that row, so the starting capacity is 14,000 BTU/hr.
How far is 600 sq ft from the neighboring capacities?
The previous capacity is 12,000 BTU/hr for 450 up to 550 sq ft. The next is 18,000 BTU/hr for 700 up to 1,000 sq ft. A sunny adjustment adds 10% to 14,000, which is 1,400, for a target of 15,400 BTU/hr. That still is not the 18,000 row.
What if the 600 sq ft space includes a kitchen?
Add 4,000 BTU/hr when the unit is used in a kitchen: 14,000 + 4,000 = 18,000 BTU/hr. The sum matches the next row capacity number, but you reached it by the kitchen adder, not because the floor area became 700 up to 1,000 sq ft.
What ceiling is this 14,000 BTU/hr figure based on?
An 8-foot ceiling. Higher ceilings are a reason to select a room air conditioner with a higher CADR. This chart does not size a central system; use the HVAC load calculator for that.