KWhCalc

AC size for a 2,000 sq ft room

40,000 BTU

for a 2,000 sq ft room (3.3 tons) · about 3,333 W at EER 12

Adjust for the room

ConditionBTU/h
Normal room40,000
Very sunny (+10%)44,000
Shaded (−10%)36,000
Kitchen (+4,000)44,000
Each extra person over 2 (+600)+600

Rule of thumb: 20 BTU per sq ft with 8 ft ceilings (ENERGY STAR sizing guidance).

Monthly running cost at $0.17/kWh

UseEnergyCost
4 h/day400 kWh$68
8 h/day800 kWh$136
12 h/day1,200 kWh$204

FAQ

What size AC for 2,000 square feet?

About 40,000 BTU (3.3 tons); add 10% for a sunny room and 4,000 BTU for a kitchen.

How much does it cost to run a 40,000 BTU AC?

At roughly 3,333 W, 8 hours a day for a month uses 800 kWh, about $136 at $0.17/kWh.