What size air conditioner do I need?

A quick estimate by area and climate. A full load calculation (Manual J) is best for a whole house.

Room or house length (ft)Room or house width (ft)ClimateSun

Cooling needed

5,000 BTU

Central AC size0.5 tons

Area168 sq ft

How to measure

Measure the room or house length and width. Pick your climate and how much sun the space gets.

Tips from the field

Bigger isn't better. An oversized AC short-cycles and leaves the house cold and clammy.
Add about 4,000 BTU for a kitchen and 600 BTU per person over two in a room.

What you'll need

Window air conditionerMini splitProgrammable thermostat

Common questions

How many BTU per square foot?

About 20 to 30 BTU per square foot, more in hot climates like the Gulf Coast.

What is a ton of air conditioning?

One ton equals 12,000 BTU of cooling per hour.

Is a bigger AC better?

No. An oversized AC cycles on and off too much and doesn't remove humidity well.

Add this calculator to your websiteFree

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