When determining the type and size of windows you need for your space, you must first determine what exactly standard window sizes are and if you will require custom windows or if typical windows will work.
Common window sizes vary depending on the function of the space, such as a standard bathroom window being smaller than a standard kitchen window.
The average window size will depend on the era the home was built in and the type of windows used. Any updates made to older homes could have enlarged the average window size to accommodate larger, more modern window openings.
The standard window dimensions for each space will be different but should fall within the popular sizes used by contractors and builders.
When building a home, standard window dimensions should be considered when determining which windows will bring in the most natural sunlight.
There are no technical or real standard window sizes, but there are what would be considered popular window sizes that most contractors and home improvement stores recommend.
Types of windows include single-hung or double-hung, casement windows, basement windows, and gliders or sliding windows. Specialty windows are window sizes that are unpopular and used less often.
Custom windows are odd-sized or shaped windows not readily found at home improvement stores or specialty window stores. Standard window sizes or popular window sizes do vary depending on the window.
Standard House Window Size
When determining what size windows are needed for your house, you need to measure all the windows that will require replacing or updating. You will notice that not all house window sizes are the same.
Usually, the bathroom, basement, and kitchen windows will vary in size. Picture or bay windows will also be of varying sizes, and while they may be standard window sizes for their type, they are still considerably larger than single-hung, double-hung, or casement windows.
It is always a good idea to have a window professional come out and measure your windows for you. Most home improvement stores, such as Lowe’s or Home Depot, offer a free assessment and on-site inspection.
Vinyl or Wood Windows
Depending on when your home was built, it will either have vinyl or wood windows. Vinyl windows are the latest and greatest in standard window sizes, as they are prefabricated and come in various sizes. Vinyl windows come in standard window sizes with a width of 18 inches to 48 inches and a height of 18 inches to 36 inches.
Wood windows are still popular, especially in homes that are true to their era. The biggest concern with wooden windows is not getting standard window sizes but the rot that can occur around the window frame.
Wood windows can come in standard window sizes with a variety of widths: 18, 20, 24, 28, 30, 32, 36, 42, 48, 54, and 60 inches and heights of 18, 20, 24, 28, 30, 36, 42, and 48 inches.
Single-Hung Window Size
Single-hung windows, along with double-hung windows, are the most common and basic types of windows. Single-hung windows resemble two windows attached and mounted vertically. They either slide up or open out, with one window panel remaining stationary at all times.
Single-hung window sizes typically include the following dimensions:
- 24 inches by 36 inches
- 24 inches by 46 inches
- 28 inches by 54 inches
- 28 inches by 66 inches
- 28 inches by 70 inches
- 34 inches by 46 inches
- 34 inches by 62 inches
Single-hung window sizes other than those listed are considered specialty or custom sizes. When replacing windows in your space, it is generally best to opt for standard window sizes rather than specialty or custom windows.
Double-Hung Window Size
Double-hung windows look like two windows attached and mounted vertically. Both frames open. Standard double-hung window sizes are ideal for living areas and bedrooms, but they can be used in any room in the house since standard double-hung windows come in several popular sizes.
Standard double-hung window sizes are 24 inches by 36 inches, 24 inches by 46 inches, 28 inches by 54 inches, 28 inches by 66 inches, 28 inches by 70 inches, 34 inches by 46 inches, or 34 inches by 62 inches.
As with single-hung window sizes, any size other than those listed for standard double-hung windows would be considered specialty or custom sizes. Standard window sizes are always the best choice for replacing double-hung windows, as they are much easier to replace.
You may be wondering what the difference between single-hung windows and double-hung windows is. See the photos below to clarify.
Watch the video below to learn about the main differences between single-hung windows and double-hung windows:
Glider Window or Sliding Window Size
Gliders, or sliding windows, have two glass panels that are side by side instead of on top of each other. These types of windows are most commonly found in bathrooms or porches, but they can be used anywhere in the house.
Standard sliding window sizes are 24 inches by 23 inches, 36 inches by 36 inches, 48 inches by 24 inches, or 48 inches by 36 inches. Standard window sizes for sliding windows are usually easy to find and replace when necessary.
Casement Window Size
Standard window sizes for casement windows come in a wide variety. Casement windows are either single-framed or double-framed. They are also either horizontal or vertical. The main difference between single-hung and double-hung casement windows is that casement windows are all open out.
Because they open out, some casement windows do not have screens on them. The ones that do have screens are opened using a hand crank.
Casement windows are generally found in kitchens, attics, basements, and bathrooms. Twin casement windows have standard casement window sizes of 21 inches by 45 inches or 21 inches by 53 inches. Single casement windows have standard casement window sizes of 25 inches by 35 inches, 29 inches by 47 inches, or 29 inches by 59 inches.
Basement Window Size
Basement windows are usually shorter than standard house window sizes. They have to fit in the small space between the top of the concrete foundation and the ground that the house sits on. Most basement windows are sliders, casement windows, or vent windows.
Some basement windows do not open at all and are stationary. Standard basement window sizes come in 32-inch widths and range in height from 15 inches to 24 inches.
Kitchen Window Size
Most kitchen windows are casement windows. Although, depending on when the home was built, they could easily still have single-hung or double-hung windows. Kitchen window size is determined by the size of the kitchen and the necessity for natural light.
Newer homes have larger custom kitchen windows that are casement windows. These are not standard window sizes and are, therefore, considered to be custom windows.
Standard kitchen window sizes include 21 inches by 45 inches, 21 inches by 53 inches, 25 inches by 35 inches, 29 inches by 47 inches, or 29 inches by 59 inches. These are common window sizes for kitchens, and any other size would be considered specialty or custom.
Bedroom Window Size
Standard bedroom window sizes can vary depending on the era the home was built. Over the past 20 years, larger windows that allow more natural sunlight into the bedroom have become increasingly popular. As a result, larger standard bedroom window sizes are now the norm. Older homes, however, often feature smaller standard bedroom window sizes.
Unless the windows are specialty or custom, finding common window sizes to suit your home’s needs should be relatively easy. Standard window sizes for bedrooms are typically:
- 24 inches by 36 inches
- 24 inches by 46 inches
- 28 inches by 54 inches
- 28 inches by 66 inches
- 28 inches by 70 inches
- 34 inches by 46 inches
- 34 inches by 62 inches
These are usually single-hung or double-hung windows.
How To Measure Replacement Windows
When replacement windows are needed and you are not sure if you have standard window sizes in your home, it is easy to measure each window. You can have a professional come to your home and measure your windows if you are not sure how to do so or you can follow this simple guide to measure for replacement windows.
First, you are going to measure the width. You will measure between the jambs at the top, middle and bottom of the window opening to get the width.
By measuring from the surface of the jambs, not from the parting beads or trim strips of the old window opening, you will get a true measurement. You will use the smallest of the three measurements as the width of the entire window.
To measure the height of a window, begin by measuring from the high point of the window sill (or the surface closest to the inside of the window) to the top of the window opening. Take three measurements: one on the right side, one on the left side, and one in the middle of the window opening. Use the smallest measurement as the height of the window.
Next, measure the depth of the window. When measuring the depth, ignore any pulleys or parting strips, as these will be removed when replacement windows are installed. For a window to be replaced with a standard size, there must be at least 3 ¼ inches between the inside window trim and the outside blind stop strip.
If the depth is less than 3 ¼ inches, it is not a standard window size. In this case, custom windows will be required, or the framing will need to be built out to accommodate standard window sizes.
Standard Window Size Chart
The chart for the typical window size is given below.
