As a rule of thumb, an air conditioner needs 20 Btu for each square foot of living space. But other considerations, such as the ceiling height and the size of your windows and doorways, might call for more cooling power. To measure your room, multiply the length by the width.

How do I calculate what size air conditioner I need?

To calculate the size of the air conditioner you need for a room, first, multiply the length of the room with its width. Then multiply it with 25 BTU to get the ample cooling for the room under different weather conditions. For example, if the room is 15 feet long and 12 feet wide, it comes to 180 square feet.

How many BTU do I need for a 20×20 room?





As a general rule, a 20×20 feet or 400 square feet room should use a 12,000 BTU or 1 Ton air conditioner. If your room is heavily shaded, you can save cost by using a 9,000 BTU or 0.75 Ton air conditioner.

How do I calculate air conditioner size for a room?

First, find out your the area of you room. Then divide it by 600 to get the basic capacity. So, if you room is 100 sq. feet, the basic AC capacity required will be 0.167 tons (100 / 600).

How big of a room will 8000 BTU cool?

about 350 square feet

At 8,000 BTU, it has the cooling capacity for up to about 350 square feet.

How many BTU do I need for a 12×12 room?





Obviously, the problem arises when you have a tiny 12×12 room, for example. According to the US Department of Energy directive, an air conditioner’s most appropriate size would be 2,880 BTU unit.

What size room can a 12000 BTU air conditioner cool?

The most common window air conditioning units come in cooling capacities ranging from 5,000 to 12,000 Btu. A 12,000 Btu air conditioner can cool between 450 and 550 square feet of floor space. A 12,000 Btu unit could cool a room 25 feet long by 20 feet wide that has 500 square feet of floor area.

What size room will a 18000 BTU air conditioner cool?

BTU Sizing Chart for Mini Split Systems

Area To Be Cooled Capacity Needed (BTUs Per Hour)
700 to 1,000 square feet 18,000 BTUs
1,000 to 1,200 square feet 21,000 BTUs
1,200 to 1,400 square feet 23,000 BTUs
Up to 1,500 square feet 24,000 BTUs

What size area will a 10000 BTU air conditioner cool?

10,000 BTUs will cover 300 sq. ft. (2,400 cubic feet)

How many BTU do I need for a 12×20 room?



How Many Square Feet Will A 5,000 – 24,000 Btu AC Cool

Cooling Capacity (BTU): Room Size: Examples:
6,000 BTU 150 – 250 sq. ft. 12×20 room
7,000 BTU 250 – 300 sq. ft. 16×16 room, 12×24 room
8,000 BTU 300 – 350 sq. ft. 18×18 room, studio apartment
9,000 BTU 350 – 400 sq. ft. 18×20 room, studio apartment

What size room will a 6000 BTU air conditioner cool?

between 100 and 300 square feet

In general, a 5,000 to 6,000 BTU air conditioner can cool between 100 and 300 square feet. Seven thousand to 8,200 BTU units are adequate for cooling 250 to 550 square feet, while 9,800 to 12,500 BTU models cool up to 950 square feet.

Can an air conditioner be too big for a room?



When an AC system is too big, it won’t run regular cycles. As a result, the cycles will not be long enough to remove humidity from the air (which is a big deal living in Florida). Generally, it takes a cycle of 20 to 30 minutes to cool and dehumidify the air.

Is higher BTU better for AC?

A measure of an air conditioner’s power is its BTU rating. BTUs are the energy used to remove heat from a room. Therefore, the more BTUs an air conditioner unit has, the better equipped it is to cool a larger space.

Is 8000 BTU too much?

Is An 8,000 BTU Unit Appropriate For Your Needs? An 8,000 BTU window AC or portable air conditioner is capable of cooling most standard bedrooms and offices. If you want to cool a larger space or multiple rooms, an 8,000 BTU air conditioner does not have enough power.

What happens if BTU is too high?

A unit with too many BTU’s, will cool the room fast, but leave the room humid. Too few BTU’s will never cool the room down and the unit will run incessantly.

How much BTU do I need?



The smaller the volume, the fewer BTUs are required to cool or heat.
Size and Ceiling Height.

Area To Be Cooled (square feet) Capacity Needed (BTUs per hour)
450 to 550 12,000
550 to 700 14,000
700 to 1,000 18,000
1,000 to 1,200 21,000

How many sq ft does a 15000 BTU AC cool?

about 875 sq. ft

Air conditioners rated at 15,000 Btu should be enough to cool most rooms up to about 875 sq. ft.

What size AC do I need for 1200 sq ft?

STEP 1: Determine how many BTUs of heating and tons of AC you need

House Square Footage BTUs Needed
500 – 700 14,000
700 – 1,000 18,000
1,000 – 1,200 21,000
1,200 – 1,400 23,000

How do you calculate BTU for a room?



Of course, BTU is not just calculated by the desired temperature, but also takes into account room size.
Calculating the BTU for your room.

Room Multiplication Factor
Bedrooms Multiply Cubic Feet by 4
Common Areas and Kitchens Multiply Cubic Feet by 3
For Rooms Facing North Add 15%
For French Windows Add 20%