What Are Standard Window Sizes?

What is a Standard Window Size?

When you are shopping for new replacement windows, you will probably notice that most of them are available in a few consistent size dimensions. These windows are designed to fit into the most common rough opening sizes in homes. They will not work for every window replacement, but it makes sense for manufacturers to produce windows that will work for most homes. To avoid paying a premium on custom windows, stick to standard window sizes when possible.

What Size Window Do I Need?

Window manufacturers will use a simple size notation for replacement windows to help you identify the size needed for your rough opening. A window’s size notation is basically width and height combined. The first two #’s are for width and the second two #’s are for height.  A 2426 Replacement Window would have a width of 2’4″ and height of 2’6″. The actual measurements of the window are usually 1/2 inch less than the whole number identifier it is labeled as.

For example, a window marked to fit a 44″ x 44″ opening will actually measure around 43 ½” x 43 ½”. That is because the manufacturer adds half an inch to each of the size dimensions so the window can be installed with ease.

The window dimensions you go for will also affect the cost of window installation in your home. Read on to learn about different windows with their standard sizes, models and their average cost by top window brands.

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Average Window Size for Homes

The most common window size is 36 inches wide by 60 inches high. However, the average window size varies by type. The reason why 36 x 60 windows are found in so many homes is because that is the most typically installed size for single-hung and double-hung windows, which are the most popular window types for U.S. homes.

Let’s take a closer look at some of the most common window types for homes and what sizes each comes in.

Sizes for 6 Popular Window Types

Regardless of which type of window you select, you need to know how to measure a window. Another handy tip to know? The most common window size across the country is two feet by three feet.

Double-Hung Window Sizes

Double-hung windows are the most common type of replacement window in the United States. They come in a wide range of sizes to fit any rough opening.

• Double-hung widths: 24″ min  to 48″ max
• Double-hung heights: 36″ min to 72″ max

Double-Hung Window Size Chart

Below, you’ll find a size chart for double-hung windows detailing the rough openings of the widths and heights.

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Check out our guide to double-hung window sizes to learn more as well as to view a size chart.

Picture Window Sizes

Picture windows are designed for architectural appeal and for allowing more light into a home. Here are the ranges for widths and heights”

• Picture window width:  24″ min to 96″ max
• Picture window height: 12″ min to 96″ max

The largest picture windows are around 8 feet x 10 feet (96 inches x 120 inches).

Picture Window Sizes Chart

The size chart below shows the rough opening heights and widths for picture windows. You can use it to help you get an idea for the general size and shape of the window as well as for finding specific model numbers of picture windows.

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Read our guide to picture window sizes to learn more.

Sliding Window Sizes

Sliding windows are usually wider than they are tall, but they also come in other shapes and sizes. Here’s the typical range of widths and heights offered standard:

• Sliding window width:  36″ min to 84″ max
• Sliding window height: 24″ min to 60″ max

Sliding Window Size Chart

You can explore all the standard sizes of a sliding window in our size chart below. Be aware that, like for other window types on this page, these sizes show the rough opening height and width for your window. We also show the model number these windows are known by.

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You can see all the standard sizes for sliding windows as well as explore the most popular sizes for homes at our guide to sliding window sizes.

Bay Window Sizes

Bay windows can help enhance any room in your home, but it is a major (and costly) project. These are the standard size ranges you can expect to come standard from manufacturers:

• Bay window width: 3’6”min to 10’6” max
• Bay window height: From 3’ min to 6’6” max.

Many homeowners find that their window is three to six feet wide and also three to six feet tall. The standard depth a bay window extends (so from the wall out to the furthest point of the window) is 18 to 24 inches.

To explore just how large these windows can get or how small you can find one in a standard size, check out our guide to bay window sizes.

Casement Window Sizes

Hinged windows that open from the side also known as replacement casement windows.

Casement window sizes have a fairly wide range of sizes that come standard: 

• Casement width: ranges from 1’ 2” to 2’ 11.5”
• Casement height: ranges from 2’ 5.5” to 6’ 5.5”

Typically, a casement window for homes will start at 2 feet (24 inches) and increase in 2-inch increments. The height starts around 4 feet (48 inches) and increases in 6-inch increments.

You can read our complete guide to casement window sizes to find the right fit for your own home.

Awning Window Sizes

Awning windows are popular in rainy regions since they are hinged at the top and open up, creating a natural awning that lets you leave the window open even in inclement weather. Here are the standard sizes they come in:

• Awning window widths: 2′ min to 3’10 1/8″ max
• Awning window heights: 1’8” min to 7’8 7/8″ max

Though they can come in larger sizes, awning windows tend to be one of the smaller (and thus cheaper) window types. The typical range homeowners choose from is two to three-and-a-half feet wide and one-and-a-half to three feet tall.

You can explore all there is to know in our guide to awning window sizes.

Custom Size Windows

If you can not locate standard sized windows to fit into the rough openings of your home, you have two options. The first is to adjust the size of your rough opening to accommodate a standard window. This is often the best option if the adjustments aren’t difficult.

The second is to order custom windows through a supplier like Lowes, Home Depot, or a local window company. You will give your window measurements to an associate and decide what frame material and glass you want for your specific window type. The supplier will help you figure out which companies can complete the order for you. You will then select the company, pay for the windows and wait for your order to be filled.

After the order is in, you will wait several weeks for the windows to be manufactured and shipped. You can either have the windows delivered to your home or go and pick them up. You will be responsible for finding a local window contractor to install them for you unless it was included in your purchase agreement. The cost of installing new windows will vary by the size and replacement window types you choose.

Older homes are especially well known for needing custom sized windows. This is because they were built before windows were being produced in mass quantities, so their windows often have odd dimensions that don’t fit standard window sizes. Dealing with custom windows is more time consuming, and there are more decisions to be made. You will also spend a great deal more money than you would with standard windows. But the benefit is that custom windows are tailored specifically for your home.