WeekendCalc

What Size AC for 500 Square Feet?

A 500 ft² room needs about 12,000 BTU of cooling. Shop for a 12,000 BTU air conditioner (1.00 tons). Adjust below for sun, ceiling height, people and kitchens.

Your project

people

Results

Cooling capacity needed
12,000 BTU/hr
Standard unit size to shop for
12,000 BTU
In tons of cooling
1.00 tons

How we got there

Room area
500 ft²
Base capacity for this area
12,000 BTU/hr
Adjustments (sun, ceiling, people, kitchen)
0 BTU/hr
  • Based on the Energy Star room-size chart, with typical adjustments for sun, ceiling height, occupancy and kitchens. If the room opens onto another space, size for both. Do not oversize: a unit that is too big cools quickly, shuts off, and leaves the air clammy.

What changes the size for a 500 ft² room

500 ft² is about 22 × 22 ft, or 50 × 10 ft, or 42 × 12 ft. The base capacity is for an average room, and the table adjusts it for the things that add or remove heat:

ConditionsBTU neededShop for
Average room (2 people, 8 ft ceiling)12,000 BTU12,000 BTU
Heavily shaded room10,800 BTU12,000 BTU
Very sunny room13,200 BTU14,000 BTU
4 people regularly in the room13,200 BTU14,000 BTU
It is a kitchen16,000 BTU18,000 BTU
10 ft ceilings15,000 BTU15,000 BTU

What kind of air conditioner is that?

This is a medium window or portable air conditioner. Most run on a standard 120 V outlet, but check the unit's amp rating against the circuit it will share.

Bigger is not better: an oversized unit cools the room quickly, shuts off, and leaves it clammy. See the full sizing guide for window, portable and mini-split options.

Want to change anything else? The calculator above is the full AC Size Calculator (BTU): edit any number and the results update instantly.

Tools & materials for this project

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Window air conditionerPortable air conditionerWindow AC insulation kitBlackout curtainsSmart thermostat plug

Frequently asked questions

What size air conditioner for 500 square feet?

About 12,000 BTU per hour, so shop for a 12,000 BTU unit. That is 1.00 tons of cooling, based on Energy Star room-size guidance for an average room.

Is a 12,000 BTU air conditioner enough for 500 sq ft?

Yes for an average room with 8 ft ceilings and two people. A very sunny room would need about 13,200 BTU, and a kitchen about 16,000 BTU, so size up in those cases.

What if my 500 sq ft room has high ceilings?

With 10 ft ceilings, the same 500 ft² needs about 15,000 BTU (15,000 BTU), because there is more air to cool.

Related sizes and guides

AC for 350 sq ft8,000 BTUAC for 400 sq ft10,000 BTUAC for 600 sq ft14,000 BTUAC for 800 sq ft18,000 BTUWhat size AC do I need?GuideSpace Heater CalculatorSize the heater for the same room

Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.