Standard Double Hung Window Sizes (with Drawings)

Replacing your windows is one of the best ways to increase your home’s value and improve its efficiency. A common window style in the US is a double-hung window. Although you can splurge on custom sizes, standard double-hung window sizes keep things much more affordable.

Standard double-hung windows range from 24 to 48 inches wide, with heights between 36 and 72 inches. Available standard size widths are 24, 28, 32, 40, 44, and 48 inches. The available standard heights for double-hung windows are 36, 44, 48, 52, 54, 60, 62, and 72 inches. But the actual size is ½ inch less than these measurements.

Replacing standard-size double-hung windows is an easy way to add instant value to your home. If you’re about to go window shopping, make sure you understand how windows sizes work.

When you purchase new or replacement windows, it’s important to know how to correctly read the dimensions. Windows aren’t always marked with measurements like 24” x 36” or 28” x 54”. So how do you know you’re getting the right size?

You need to understand how manufacturers label window sizes. They do it with four-digit numbers called size notions or call sizes. The first two digits represent the width, and the last two digits represent the height.

Within each pair of digits, you can determine the feet and inches. For example, if a window is 24” by 36”, the four-digit identifier would be 2030.

The two stands for two feet wide, the zero stands for zero inches. Then, the three stands for three feet high, and the zero again is for zero inches. If a window is 28” by 54,” the four-digit number would be 2446 (meaning 2’4” x 4’6”).

Typically, vinyl and aluminum windows’ call sizes include the frame, sash, and glass. Wood windows usually don’t include the frame in their call sizes, and instead, they refer to only the glass. So a wood window that’s 36 inches wide would actually be closer to 37 ½” when you add in the frame.

In most cases, a wood window with the same call size as a vinyl window would have more visible glass. But, since manufacturers can vary on how they label their windows, it’s always wise to ask for details.

Installing two separate windows side by side essentially doubles the width of your individual window. But, you can also purchase ready-to-go twin double-hung windows that are encompassed within one single frame.

Many times, manufacturers might have these styles of windows available in custom sizes. You can find tons of different sizes depending on where you shop. For example, this size chart from America Craftsman features countless sizes of twin double-hung windows.

The smallest starts at 18” by 30”, and the largest is 48” x 62”. Other companies will likely offer similar sizes. Therefore, it’s always wise to shop around and ask for details.

Measuring properly for windows is critical to getting precisely what you need. If you’re not confident with your number, it would be a good idea to have a professional do the measuring. For new construction, your contractor or window installer should take care of it.

If you’re purchasing replacement windows, the company or your installer should come out and measure. This service is typically included in the cost of the windows and installation.

But, if you’re confident in your DIY measuring skills, keep these tips in mind.

Changing the window opening size is possible, but it’s best left to a professional. Once you start changing walls, you’ll likely need a permit anyway. Plus, if putting in a smaller window, you need to make sure you properly close in the extra space.

It’s important to consider your home’s structural integrity, efficiency, and overall look. Putting a smaller window in a larger opening doesn’t always mean you need a custom window.

In fact, you might be opting for a smaller window to get a standard size. However, you will still need a contractor or professional installer to handle closing in the area properly.