What are Standard Window Sizes?

A comprehensive guide to standard window sizes for all types of windows and window measurements.

If you’re looking to replace a window, you can just hop online and order a small, medium, or large, right? 

Well, unfortunately, no. 

Windows aren’t like coffee. There’s no tall, grande, or venti to choose from. You may have an idea of what the average size of a window looks like in your home, but when it comes to actual measurements, you’ll quickly find that a “standard” size is a rare find. From modern homes to historical houses, windows vary in size, style, and even material. 

So where do you start? 

Despite the variety, there are some rules you can follow when it comes to finding the right window size for your home. Join us as we take a look at standard sizes, standard materials, and how you can sound like a window pro on your next trip to the hardware store.  

What is a standard window size? 

A standard window size refers to the most common window measurements. If you’ve ever worked with lumber, you’ve probably heard someone talk about a 2×4—that’s a standard size for wood. 

Windows, however, are a little more complicated. 

Is there a standard window size?  

Yes and no. Windows come in all shapes and sizes, including custom, so there aren’t just a few standard sizes to choose from. That said, each style of window tends to have its own standard sizes across most home designs. If you know your style, you can usually narrow down the options.  

However, even those options can have surprise variations. Measurements are measurements, but different brands and manufacturers might have different definitions of “standard.” A “standard” double-hung window from one company might have slightly different measurements than the company down the street. 

When in doubt, it’s always best to determine window size with a tape measure, rather than an assumption.

Check out our in-depth guide for a full breakdown of how to measure your windows. 

How do you read a window size? 

When measuring and ordering windows, you need to speak the same language as your manufacturer. So when talking about window size, keep in mind that you’ll always measure your width and then your height.

Window size is written down as width (feet and inches) and height (feet and inches). These two numbers are combined into one four-digit number with the first two digits representing the width and the second two digits representing the height. 

For example, if you needed a window with a 3’8” width and a 2’2” height, the window size would read 3822. If you went to a manufacturer and asked for a 3822 window, they’d know what size you meant. (That’s for those of us in the U.S. who measure in feet and inches…metric is a whole different ball game!)

It’s also worth noting that window measurements on the window and their measurements in real life won’t match. So don’t panic! Manufacturers will usually lop off about a half-inch on both sides of the physical window to make sure it fits, meaning a 36” window will actually measure 35.5” with a measuring tape.  

What size are standard windows? 

Though window sizes vary, there is a standard range of sizes for different types of windows. 

What is the standard bedroom window size? 

Most bedroom windows are either double- or single-hung windows unless you invest in a large picture window style. If you have another style, these sizes don’t apply. But for the majority of homeowners, your bedroom windows should fall between these dimensions: 

WIDTH: 24” – 34”

HEIGHT: 36” – 62”

If your bedroom has a bay window or other more elaborate setup, you might not be dealing with a standard size. In that case, you’ll want to measure the custom dimensions yourself.

casement window example window nationWhat are standard casement window sizes? 

Casement windows open towards the exterior of a home on a hinge and are one of the most popular choices for airflow. However, they do tend to run on the smaller side overall compared to double-hung or sliding windows. Most casement windows fall between these dimensions: 

WIDTH: 14” – 36” or 1.2’ – 3’

HEIGHT: 30” – 78” or 2.5’ – 6.5’

A note from the pros: Casement windows tend to have less leeway in manufacturing dimensions because the leverage required to operate their opening mechanism stops working effectively after you reach 36” x 78” (or 3678).

What are standard double-hung window sizes? 

Double-hung windows are the most common type of window in modern home architecture. They’re made of two window sashes that move up and down to open and close via a latch system. Because of their popularity, they come in nearly any size you need, but the most common double-hung sizes fall between these dimensions: 

WIDTH: 24” – 48” or 2’ – 4’

HEIGHT: 36” – 72” or 3’ – 6’

These sizes also apply to single-hung windows. Additionally, you should note that these size ranges are larger than the bedroom window size ranges even though both largely refer to double-hung windows. That’s because these size ranges apply to all rooms, not just the bedroom.  

Sliding WindowsWhat are standard sliding window sizes? 

Sliding windows are almost identical to double-hung windows, but they slide open horizontally. They still have two sashes, but they open left-to-right instead of top-to-bottom. Unlike double-hung windows, sliding windows almost always have a larger width than height. The most common sliding window sizes come in the following dimensions: 

WIDTH: 36” – 84” or 3’ – 7’ 

HEIGHT: 24” – 60” or 2 ’- 5’

Like double-hung windows, sliding windows are commonly found in all types of rooms. 

picture windowWhat are standard picture window sizes? 

Picture windows are typically quite large, as their main appeal is their ability to provide uninterrupted light and amazing views. However, because picture windows are constructed from a single massive sheet of glass, installation can be more expensive due to increased risk. The standard ranges for picture window sizes are: 

WIDTH: 24” – 96” or 2’ – 8’ 

HEIGHT: 24” – 62” or 2’ – 5.2’

What are standard bay window sizes? 

Bay windows, like picture windows, tend to run on the larger side. However, unlike picture windows, bay windows can be installed to open and close. That means that when you’re looking at bay window sizing, you’re actually looking at the sizing of three different window panels—frequently double-hung, single-hung, or casement. The size ranges below refer to the entire width and height of the bay window, not the individual components:  

WIDTH: 42” – 126” or 3.5’ – 10.5’

HEIGHT: 36” – 78” or 3’ – 6.5’

What are other important window measurements? 

Not all window measurements are about the entire window. Let’s take a look at a few standard measurements for specific window parts. Keep in mind that, just like the full-window sizes, these are all averages; each window part should still always be measured before ordering a replacement. 

Standard window frame thickness

Window frame thickness comes down to two key factors: the material of the frame and the location of the home. Homes in areas with extreme weather will normally have thicker walls and need a thicker frame to accommodate the space—although you can choose a thinner frame for aesthetics. Additionally, the thickness depends on your frame material, though all float around 0.5 inches: 

Wooden frames: 10mm – 20mm

Aluminum frames: 16mm-26mm

uPVC frames: 20mm-28mm

There aren’t any strict regulations when it comes to window frame thickness, but if you know you’re up against the elements every year, the thicker you can go, the better. 

Window glass size

Window glass size aligns with the size of your frame and the style of your window. Window glass thickness, however, is up to you. No matter what type of glass you choose, most window glass comes in two basic thickness measurements: 

Single strength: 3/64” thick

Double strength: ⅛” thick 

The overall window thickness also depends on the number of panes you choose for your window. For instance, a single-paned, single-strength window would only be 3/64” thick. However, a triple-paned, double-strength window would have three panes of glass measuring at ⅛” thick plus the space in between the panes. Space in between your double- or triple-paned glass varies, but can be as wide as an inch to accommodate gas fillers to improve insulation.

In general, when looking at window thickness, more glass means more soundproofing and more temperature regulation. It also can mean a higher price, but the balance is often worth it depending on your climate. 

Are window screens standard sizes? 

Yes. Window screens, unlike windows, come in standard sizes because they don’t have to fit the entire window. The three most common standard screen sizes are: 

  1. 18” x 14” 
  2. 18” x 18” 
  3. 20” x 20”

That said, you can get a screen in any size you need for any window that opens and closes. You simply may have to pay more for a custom size—especially if it’s not a square or rectangle. 

Ensure you’re ordering correctly sized windows by consulting the experts 

Not sure what window size you need? No problem. When it comes to home window replacements, Window Nation is here to answer all your questions. We make ordering and installation easy—no matter your home renovation savvy. With a focus on quality, efficiency, and long-lasting expert installation, we’re happy to work with you to complete the window project of your dreams. We can even help you design custom-sized vinyl windows for that long-awaited remodel.

Contact Window Nation today for a free quote.

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