What Size Air Conditioner Do I Need for a 200 Sq Ft Room?
200 sq ft is inside the 6,000 BTU/hr band, not on a line between two capacities.
Full breakdown: BTU per square foot.
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Capacity from the chart
| Area to be cooled | Capacity needed | Source |
|---|---|---|
| 150 up to 250 sq ft | 6,000 BTU/hr | ENERGY STAR |
Confirm the area before you trust the row. Multiply length by width. A 200 sq ft result is not the 100 up to 150 row (5,000 BTU/hr) and it is not the 250 up to 300 row (7,000 BTU/hr). Only a measurement that actually crosses 150 or 250 sq ft changes the row. Shade is not a substitute for that measurement.
How to size it
Start at 6,000 BTU/hr and apply the adjustment that matches the room. Use shade or sun, not both. Add people only when more than two people are in the room regularly. Add the kitchen figure only when the unit is used in a kitchen.
| Adjustment | On the 6,000 row | Source |
|---|---|---|
| Heavily shaded, reduce capacity 10% | 6,000 − 10% = 5,400 BTU/hr | ENERGY STAR |
| Very sunny, increase capacity 10% | 6,000 + 10% = 6,600 BTU/hr | ENERGY STAR |
| Each additional person beyond two | 6,000 + 600 BTU/hr = 6,600 BTU/hr | ENERGY STAR |
| Unit used in a kitchen | 6,000 + 4,000 BTU/hr = 10,000 BTU/hr | ENERGY STAR |
10% of 6,000 BTU/hr is 600 BTU/hr (6,000 × 10%).
On this particular row, 10% of 6,000 is 600 BTU/hr, which is the same count as the 600 BTU/hr person adder. They are not the same step. A shaded 200 sq ft room with only the usual occupancy is 6,000 − 10% = 5,400 BTU/hr. A sunny 200 sq ft room is 6,000 + 10% = 6,600 BTU/hr. A sunny room that also has one person beyond two is 6,000 + 10% + 600, which is 6,600 + 600 = 7,200 BTU/hr. A kitchen use of the same row is a different jump: 6,000 + 4,000 = 10,000 BTU/hr.
Installation matters at this size because the unit is small and the sash gap is a large share of its airflow. ENERGY STAR says an improperly installed room air conditioner leaks as much air as a 6-square-inch hole. Foam around the sash is the accessory that matches that warning.
Every figure above assumes the chart's 8-foot ceiling. For a taller room, ENERGY STAR does not publish a foot-by-foot adder. The note is to select a room air conditioner with a higher CADR.
A ductless head for the same floor area is a different purchase. That path is the mini-split room size guide.
6,000 BTU window air conditioners on Amazon Window air conditioner insulation foam on Amazon
Related questions
- What size air conditioner for a 150 sq ft room
- What size air conditioner for a 250 sq ft room
- What size air conditioner for a 300 sq ft room
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 does a 200 sq ft room need?
ENERGY STAR puts 150 up to 250 sq ft at 6,000 BTU/hr. A 200 sq ft room is inside that band, so the starting capacity is 6,000 BTU/hr, not the 5,000 row below it and not the 7,000 row above it.
Does shade drop a 200 sq ft room to 5,000 BTU/hr?
No. Heavy shade reduces the chosen row by 10%. Ten percent of 6,000 is 600, and 6,000 − 600 = 5,400 BTU/hr. The room stays on the 150 up to 250 row; the percent does not move it into 100 up to 150.
How much do people and a kitchen add in a 200 sq ft room?
Each person beyond two adds 600 BTU/hr, so 6,000 + 600 = 6,600 BTU/hr. A unit used in a kitchen adds 4,000 BTU/hr, so 6,000 + 4,000 = 10,000 BTU/hr. On this row the shade swing and the person adder are both 600 BTU/hr, and they still count separately.
What if the window unit leaks around the sash?
The chart assumes an 8-foot ceiling. Separately, ENERGY STAR says an improperly installed room air conditioner leaks as much air as a 6-square-inch hole. A higher ceiling is a reason to select a room air conditioner with a higher CADR, and a central system still belongs on the HVAC load calculator.