Standard Window Sizes

What Are Standard Window Sizes?

When shopping for windows you’ll probably notice that most of the windows available seem to be in a few consistent dimensions. These windows are designed to fit into the most common rough opening sizes in homes around the country. They won’t work for every window replacement, but it makes sense to produce windows that will work for most people. To avoid paying a premium on custom windows, stick to these standard window sizes when possible.

Understanding Standard Measurements

When you go to the local home improvement store you’ll see windows listed in whole number dimensions. Just because you see a window designed to fit a whole number measurement doesn’t mean that the window has exact whole number dimensions. For example a window marked to fit a 44″ x 44″ opening will actually measure around 43 ½” x 43 ½”. That’s because the manufacturer removes a half inch from each of the dimensions so the window can be installed with ease.

Window Size Notation

Windows are given special size notation that’s simple to understand. It’s important to understand this size notation when you’re shopping for windows. When you know how to read it you can pick out windows easily.

Size notation is split into four digits, the first two are for width and the second two are for height.

To give you an example of size notation, a 2426 window would be 2’4″ wide and 2’6″ tall. The first digit of the notation standards for feet and the second stands for inches. If you want a window that is 44″ wide or 3’8″ you would want a 38 window. If you want a window that’s 44″ wide and 60″ tall you would want a 3850 with the 50 signifying 5’0″ or 60″ overall. There is a bit of a learning curve but once you understand window size notation you’ll be able to quickly select the right window for your home.

A 2020 Window

One of the most common window rough openings in a home measures 24 x 24 inches or two feet by two feet in size. Since these dimensions are so common in new homes and many older homes as well, there are windows known as 2020 windows designed to fit this space. The windows are 2′ 2″ x 2′ 2″ in size or 24″ x 24″ minus the half inch allowance from both the height and width of the window.

When you go to the store and you see a 2020 window, it’s actually 23 ½” x 23 ½” in size. It is made for the very common 24″ x 24″ rough opening and is readily available.

A 3838 Window

Another common window opening is 44″ x 44″. The windows fit for these openings are known as 3838 windows. They are given this name because they are 3’8″ x 3’8″ or 44″ x 44″ in size, minus the ½” allowance. That means a 3838 window is actually 43 ½” x 43 ½” in size.

standard window sizes

The Benefit of Standard Rough Openings

It’s simple to order windows in custom dimensions but it’s also quite expensive compared to the standard windows that you’ll find on the shelves since they are not produced in as large of quantities and in some cases they actually have to be crafted specifically for you.

If your home has standard rough openings you can choose from a variety of pre-made windows that can be put right into those openings.

If you don’t have standard openings you can adjust the dimensions of your existing openings to make them standard. Generally it is easiest to reduce the size of your opening by adding wood to the window frame, but the frame can also be expanded with new headers to meet any size that you want. If you are tired of relying on custom windows you can simply adjust the openings to a more standard size and start shopping the available standard options but you’ll likely want to seek the help of a professional if you choose to go this route.

What are Standard Rough Opening Sizes?

Standard rough opening sizes are different depending on the type of window that you have. If you are looking for standard windows to fit your rough opening it might be worth it to consider a different type of window to fit your rough opening dimensions.

Double Hung Windows Standard Sizes

Standard Window Sizes Doublehung
Double hung windows are the most popular type of window in the United States and they have a wide variety of standard sizes to choose from.The most common widths and available are:

Widths

  • 24″
  • 28″
  • 32″
  • 40″
  • 44″
  • 48″

Heights

  • 36″
  • 44″
  • 48″
  • 52″
  • 54″
  • 60″
  • 62″
  • 72″

Picture Windows Standard Sizes

Standard Window Sizes Picture
Picture windows are designed for their architectural appeal and for bringing light into a home. They generally don’t open and are built in a wide variety of sizes.

Widths

  • 24″
  • 36″
  • 48″
  • 60″
  • 72″
  • 96″

Heights

  • 12″
  • 18″
  • 24″
  • 36″
  • 48″
  • 52″
  • 60″
  • 62″
  • 72″
  • 96″

You have a lot of options to work with when considering picture windows. If you have an opening that fits one of these dimensions you can likely have picture windows put in without needing to custom order them.

Single Slider Windows Standard Sizes

Standard Window Sizes Single Slider
Single slider windows are less common, but they are offered by a wide variety of manufacturers and come in standard sizes.

Widths

  • 36″
  • 48″
  • 60″
  • 72″
  • 84″

Heights

  • 24″
  • 36″
  • 48″
  • 60″

Slider windows are actually wider than they are tall. If you have dimensions that fit into this range you can pick up an off-the-shelf slider and have it installed without special ordering.

Obtaining Windows Quickly

In order to get windows in your home as quickly as possible, you want to rely on standard windows since they are already produced and sitting in warehouses and on shelves around the country. Custom windows have to be created or shipped from a specialized location. When you have a broken window you want to replace right away, or if you want to get a new window in for a weekend project and you can’t wait another week or two to get started, standard windows are the way to go.

measuring-skylight

Ordering Custom Window Sizes

When you can’t locate standard sized windows to fit into the rough openings of your home you really only have two options remaining. The first is to adjust the size of your rough opening to accommodate a standard window, this is sometimes the best option if the adjustments aren’t difficult to make. The second is to order custom windows.

If you decide to go with custom windows you’ll have to work with a supplier like Lowes, Home Depot or a local window supplier to help you get the custom windows you need created. First you sit down and talk with an associate about the type of windows that you need and supply him with the measurements. You’ll talk through the different window features and decide what frame material and glass type you want. Then the supplier can help you figure out which companies can complete the order for you. You’ll then select the company, pay for the windows and wait for your order to be filled.

After the order is in, you’ll wait several weeks for the windows to be manufactured and shipped. You can either have the windows delivered to your location or go and pick them up, you’ll be responsible for finding the professionals to install them for you as well unless that was part of your purchase agreement.

Dealing with custom windows is more time consuming, there are more decisions to be made, and you’ll spend a great deal more money than you would with standard windows. The benefit of dealing with custom windows is that you’ll have more feature options to choose from and you can get windows specified for your home.

Generally when you are purchasing windows for your home you’ll be looking at standard windows, especially when you are just getting replacement windows. Standard sizes are very common in new construction or homes built within the last 30 years.

Older homes often have windows of odd dimensions that must be custom ordered or adjusted to standard dimensions since these homes were built before windows were being produced in mass quantities. If you’re hoping to save money when replacing your windows you should use standard dimensions if at all possible.

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