Window AC Dimensions: Width, Height & Depth

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Small window air conditioners start at 14” wide and 11” tall. Large window air conditioners are as wide as 28” and as tall as 22” – a few are taller.

There is one very low profile window AC, the Kapsul W5, which is only 7” tall – but delivers just 5,000 BTU of air conditioning (and is prohibitively expensive).

If you need a narrow window air conditioner, consider a casement window AC. They’re produced in 8,000 and 10,000 BTU with a narrow width of 15.5” or 16”.

Window Air Conditioner Dimensions

Here is a window AC size chart from 5,000 to 35,000 BTU window air conditioners.

Window AC Dimensions

Window Air Conditioner Dimensions

Cooling CapacityWidthHeightDepth
5,000 Btu15 – 20 Inches7 – 15 Inches12 – 23 Inches
6,000 Btu14 – 21 Inches11 – 20 Inches12 – 24 Inches
6,200 Btu16 – 21 Inches12 Inches18 Inches
8,000 Btu14 – 26 Inches12 – 24 Inches12 – 29 Inches
8,200 Btu24 Inches15 Inches22 Inches
9,500 Btu20 Inches12 – 14 Inches21 – 25 Inches
10,000 Btu14 – 26 Inches13 – 22 Inches16 – 29 Inches
11,000 Btu23 Inches15 Inches23 Inches
12,000 Btu19 – 26 Inches13 – 22 Inches16 – 29 Inches
13,600 Btu26 Inches16 – 18 Inches29 Inches
14,000 Btu19 – 24 Inches15 – 16 Inches21 – 29 Inches
14,500 Btu19 – 21 Inches15 – 19 Inches15 – 22 Inches
15,000 Btu20 – 26 Inches15 – 18 Inches23 – 28 Inches
17,500 Btu26 Inches18 Inches29 Inches
18,000 Btu20 – 26 Inches15 – 24 Inches18 – 31 Inches
20,000 Btu26 Inches18 Inches29 Inches
21,500 Btu26 Inches18 Inches29 Inches
22,000 Btu26 Inches18 Inches26 Inches
23,000 Btu26 – 28 Inches17 – 20 Inches31 – 36 Inches
23,500 Btu26 Inches18 Inches26 – 31 Inches
24,000 Btu26 – 28 Inches19 – 20 Inches26 – 36 Inches
24,500 Btu26 Inches18 Inches28 Inches
25,000 Btu27 Inches19 – 27 Inches19 – 27 Inches
28,000 Btu27 – 28 Inches19 – 20 Inches27 – 36 Inches
35,000 Btu28 Inches20 Inches36 Inches

Note: This data is based on 212 popular window ACs on the market.

That’s right. We have done the research looking at more than 200 window air conditioner models to produce the most comprehensive list of window AC dimensions.

Minimum & Maximum Window Width for Window AC Installation

The minimum window width of a window air conditioner is 15.5” for a casement window air conditioner and 21” for a standard window air conditioner.

casement window air conditioner

The maximum window width of a window air conditioner is 41”.

The max width accounts for the side panels fully extended. 

Cooling CapacityMinimum Window WidthMaximum Window Width
5,000 Btu21 Inches38 Inches
6,000 Btu21 Inches36 Inches
6,200 Btu27 Inches39 Inches
7,500 Btu22 Inches36 Inches
8,000 Btu15.5 Inches (casement)36 Inches
8,200 Btu23 Inches36 Inches
10,000 Btu16 Inches (casement)39 Inches
10,200 Btu22 Inches36 Inches
12,000 Btu23 Inches39 Inches
14,000 Btu24 Inches40 Inches
15,000 Btu28 Inches41 Inches
18,000 Btu28 Inches41 Inches
22,000 Btu29 Inches41 Inches
23,000 Btu29 Inches41 Inches
23,500 Btu30 Inches39 Inches
24,000 Btu30 Inches41 Inches
24,500 Btu29 Inches41 Inches

The minimum width for 8,000 and 10,000 BTU window air conditioners includes casement window ACs designed to be narrow enough for use with a casement window. Some of these can also be used in sliding or gliding windows.

For standard window ACs that fit into single-hung and double-hung windows, the minimum width is around 21” to 23” depending on AC BTU capacity.

Can you put an air conditioner in a small window?

Yes, but it will have to be a window AC with 5,000 to 8,000 BTU capacity max.

Minimum Window Height for Window Air Conditioner Installation

Minimum window height is 12” to 20”.

This means the window must open at least this much to provide room for the AC.

Minimum Window Height for Window Air Conditioner Installation

Cooling CapacityMinimum Window Height
5,000 Btu7 Inches
6,000 Btu12 Inches
6,200 Btu14 Inches
7,500 Btu14 Inches
8,000 Btu13 Inches
8,200 Btu16 Inches
10,000 Btu14 Inches
10,200 Btu16 Inches
11,000 Btu17 Inches
12,000 Btu14 Inches
14,000 Btu16 Inches
15,000 Btu19 Inches
18,000 Btu18 Inches
22,000 Btu19 Inches
23,000 Btu18 Inches
23,500 Btu20 Inches
24,000 Btu20 Inches
25,000 Btu20 Inches
28,000 Btu20 Inches

What is the smallest height window air conditioner?

7” – and only the Kapsul W5 is 7”. Others are higher.

There are very few low profile window air conditioners less than 12” in height.

10 – 16 Inches Height Low Profile Window Air Conditioners

How high does a window open for an AC?

At least 7”, but most window ACs need 12” of height or more.

Kapsul W5 Window Air Conditioner
Kapsulair W5

10 – 16 inches height Low Profile Window Air Conditioners

10 inch height window AC

11 inch height window AC

  • N/A or None Available

12 inch height window AC

13 inch height window AC

14 inch height window AC

  • Midea MAW05R1WBL

16 inch height window AC

  • Della 048-TL-WAC5K

As you can see, you have options. Make sure to accurately measure the window opening to know the most narrow or the minimum window opening to accommodate an AC.

How Do You Measure a Window for an Air Conditioner?

The dimensions are given in width x height. If there is a third dimension, it is the depth.

1 – Open the window fully

2 – Use a tape measure to measure the width of the window at the most narrow part

3 – Measure the height of the window opening from the bottom of the window sash to the highest point of the windowsill

In short, measure the window side to side and top to bottom. Make sure the window air conditioner you choose fits inside those window dimensions.

What Is the Standard Size of a Window Air Conditioner?

16” to 26” wide by 12” to 18” high.

There are more narrow units available. Taller units are usually casement window air conditioners.

Here are average sizes.

  • 6,000 BTU: 14” to 21” wide x 11” to 20” high
  • 8,000 BTU: 14” to 26” wide x 12” to 24” high (including casement ACs)
  • 10,000 BTU: 14” to 26” wide x 13” to 22” high (including casement)
  • 12,000 BTU: 19” to 26” wide x 13” to 22” high 
  • 15,000 BTU: 20” to 26” wide x 15” to 18” high
  • 18,000 BTU: 20” to 26” wide x 15” to 24” high
  • 20,000 BTU: Average 26” wide x 18” high
  • 24,000 BTU: 26” to 28” wide x 19” to 20” high
  • 35,000 BTU: Average 28” wide to 20” high


How much space is needed behind a window AC?

Between 8” and 18”.

Determine if a window air conditioner will fit in your space when depth is limited. To do this, measure the part of the AC that will stick outside the window.

Do window air conditioners fit all windows?

No. Measure your window opening for minimum width and height requirements. And then check the specs on the AC. The information on most product pages or AC boxes tell you what the minimum and maximum window openings are for the unit.

If you want to put a window AC in a casement window, you’ll need to choose a unit called a casement window AC. It will be narrow but taller than most other window air conditioners.

What should be the size of window for window AC?

At least 21” wide and 12” high.

But a window with a wider frame and one that opens more than 12” will allow you to use a larger size AC.

Can a window be too big for AC unit?

Yes. A window can be too wide and too high for an air conditioner.

Too wide: When the side panels of an AC are fully opened, total width is 38” to 41”. If the window is wider, you will need to fill the gap between the panels and the window frame with plastic, insulation or other material that blocks air leaks.

Too tall: If you want a unit in a casement window, first choose one designed for that window type. Even then, the panels provided might not fill the space above the AC, and you will have to improvise to stop issues like air leaks and insects.

What is a casement window air conditioner?

It is a window AC with a narrow width and taller profile. The AC is designed to fit in a casement window rather than a sash window that opens vertically. Height is greater than width unlike more window air conditioners. 

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications. Protection Status