Room size → BTU, tonnage & unit type
Short answer
A 1 ton (12,000 BTU) AC cools roughly 600 sq ft in a temperate climate — about 480 sq ft in a hot climate up to 670 sq ft in a cooler one. Insulation, ceiling height, sun, and occupancy shift the real figure.
Capacity
12,000 BTU
Typical room
600 sq ft
Hot climate
480 sq ft
Cool climate
670 sq ft
A 1 ton air conditioner is 12,000 BTU (tonnage is just BTU ÷ 12,000). At the ~20 BTU/sq-ft baseline that covers about 600 square feet in a temperate climate — roughly 480 sq ft where summers are hot, up to 670 sq ft in a cooler climate.
Insulation, ceiling height, sun exposure, and how many people use the room all shift the real figure. An oversized unit short-cycles and leaves the room humid, so match the capacity to the space rather than over-buying.
Real, widely available units in the Up to 12,000 BTU class. Independent picks — we're not affiliated with any manufacturer or retailer and earn nothing from these links. Always match the unit's BTU to the size above.
Best overall
8,000–12,000 BTU
Window · inverter · U-shape · ~36 dBA · window still opens
The U-shape puts the compressor outside the glass, so it runs about as quiet as a whisper and you can still open the window. Inverter compressor sips power.
Find on AmazonQuietest
8,000–14,000 BTU
Window · dual inverter · Dual-inverter · Wi-Fi · very quiet
LG’s dual-inverter compressor ramps up and down instead of cycling on/off — quieter, steadier temps, and lower running cost than a fixed-speed unit.
Find on AmazonBudget pick
5,000 BTU
Window · fixed-speed · Cheapest way to cool a small room
A no-frills window unit that reliably cools a small bedroom, office, or dorm up to ~150 sq ft for the lowest upfront cost.
Find on AmazonBest value
8,000–12,000 BTU (SACC)
Portable · inverter · No permanent mount · inverter
When a window mount isn’t an option, this inverter portable is one of the few that actually cools like its rating instead of falling short.
Find on AmazonA 1 ton unit is 12,000 BTU and cools about 600 sq ft in a temperate climate — roughly 480–670 sq ft depending on climate, insulation, and sun.
12,000 BTU. Air-conditioner tonnage is just BTU ÷ 12,000, so 1 × 12,000 = 12,000 BTU.
An oversized AC short-cycles — it cools fast but leaves the room humid and wastes energy. If your room is well under 480 sq ft, size down. Enter your room in the calculator to check.