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What size air conditioner for 2,000 sq ft?

ENERGY STAR recommends about 30,000 BTU to cool 2,000 square feet, so a 30,000 BTU unit (2.5 tons). Adjust for sunlight, people and ceiling height below.

Method: ENERGY STAR room air conditioner sizing chart with its official adjustments for sun, people and kitchens.

sq ft
Sunlight
ft

Cooling capacity needed

30,000 BTU

Buy a 30,000 BTU unit · 2.5 tons · 2,000 sq ft

ENERGY STAR base for 2000 sq ft30,000
Total30,000 BTU
  • • Bigger isn't better: an oversized AC cools too fast to remove humidity, leaving the room cold and clammy.
  • • At this size you're cooling a whole floor or house. For central air or a ducted heat pump, ask an HVAC contractor for a Manual J load calculation.

ENERGY STAR AC size chart

Area to coolCapacity neededTons
100–150 sq ft5,000 BTU/h0.4
150–250 sq ft6,000 BTU/h0.5
250–300 sq ft7,000 BTU/h0.6
300–350 sq ft8,000 BTU/h0.7
350–400 sq ft9,000 BTU/h0.8
400–450 sq ft10,000 BTU/h0.8
450–550 sq ft12,000 BTU/h1
550–700 sq ft14,000 BTU/h1.2
700–1,000 sq ft18,000 BTU/h1.5
1,000–1,200 sq ft21,000 BTU/h1.8
1,200–1,400 sq ft23,000 BTU/h1.9
1,400–1,500 sq ft24,000 BTU/h2
1,500–2,000 sq ft30,000 BTU/h2.5
2,000–2,500 sq ft34,000 BTU/h2.8

How the calculation works

The base capacity comes from the ENERGY STAR room air conditioner sizing chart, which assumes 8 ft ceilings. ENERGY STAR then recommends four adjustments: reduce capacity by 10% for a heavily shaded room, increase it by 10% for a very sunny room, add 600 BTU for each person beyond two who regularly uses the room, and add 4,000 BTU if the unit is for a kitchen. For taller ceilings, the calculator scales the result by ceiling height, a common industry adjustment.

For whole-house central air or heat pumps, an HVAC contractor should run a Manual J load calculation, which also accounts for insulation, windows and your local climate.

More AC size guides

Frequently asked questions

How many BTU do I need per square foot?

ENERGY STAR's chart works out to roughly 20 BTU per square foot for typical rooms, adjusted for sun, people and kitchens.

What size AC for a 12x12 room?

A 12′ × 12′ room is 144 sq ft, which needs 5,000 BTU according to ENERGY STAR. A sunny room needs about 5,500 BTU, so a 6,000 BTU unit.

What size AC for 1,000 sq ft?

ENERGY STAR recommends 18,000 BTU, or 1.5 tons, for 700–1,000 sq ft.

Is a bigger air conditioner better?

No. An oversized unit cools the room before it removes humidity, so the room feels cold and clammy and the unit wears out faster.

How many square feet does 1 ton of AC cool?

One ton is 12,000 BTU, which ENERGY STAR matches to 450–550 sq ft.