What is the Standard Size of a Bathroom Window?

Windows are the essential part of the bathroom which allows sunlight and fresh air. It is a wide opening in the wall, covered and framed with different types of glasses and wooden planks.

What is the Standard Size of a Bathroom Window? The standard size of a bathroom window is 12, 18, or 24 inches wide and a height of 18 or 24 inches, depending on the size and location of the bathroom, type of window, building codes of the state, and the ventilation and privacy requirements. You can select different types of windows for the bathroom, such as awning, transom, sliding sash, hopper, and casement windows with different average widths and heights.

Different size openings allow the house owners to enjoy the beautiful views outside the house. The standard size for these windows may vary for different locations and states, depending on the size of the place.

What is the standard window size for the bathroom?

The standard window sizes depend on the ventilation and privacy required in this place. There are three standard sizes for bathroom windows.

The first is a square bathroom window which has a standard size of 24×24 inches or 2×2 feet, which is equivalent to approximately 61×61 centimeters.

The second standard size is 18×24 inches or 1.5×2 feet (46×61 centimeters). Another standard size for a small place is 12×24 inches or 1×2 feet, which is equal to 30×61 centimeters.

You can select any standard size, which can go well with the interior and enhance the overall appearance of this place. All you need to consider is the building code and the airflow required for this place for a healthy and fresh atmosphere.

Different types of windows in the bathroom and their standard sizes

You can install different types of windows in the bathrooms, and all have different standard heights and widths. Some of these are listed here.

Awning Windows

Awning windows are a popular and common choice for bathrooms, as they take less space and open outward because they are hinged on the top of the frame.

You can open them from the bottom with the crank on a handle at the bottom side. They are designed for smaller and larger places, as manufacturers make different frame sizes.

They look stylish and prevent rain inside this place. You can customize any size and design according to the wall space and the interior.

Their average width is 12-96 inches, and their average height is 12-60 inches. As a result, they offer good ventilation and moderate sunlight as they swing outward and restrict the direct and intense light.

Transom windows

They are decorative frames or glass placed above the window and door.

They can enhance the overall interior, allow more sunlight, and fills the extra space above the door. The extra sunlight coming through these openings makes the place look more bright and spacious.

They are available an average width of 6 to 24 inches, and the average height ranges from 6 to 24 inches. You can select a different size depending on the space above it and the area you want to fill. 

Sliding sash windows

Sliding sash windows are vertical sliders and are best for the bathroom with less horizontal wall space. They have two vertical sliders, which offer you to slide any of them to allow light and air into this place.

They are the most common, easy to use, and known for their space-saving properties.

They look attractive as you can select different colors and hardware accessories to match the bathroom interior. They have an average width of 36-84 inches and a height of 24-60 inches. 

Hopper windows

They are similar to transom windows and are usually installed high on the wall. However, they open inward, unlike the awning ones, which open outward.

They are usually installed in the basement bathrooms and are perfect for places with less direct light sources. In addition, they offer adequate ventilation, a sleek look, and fresh air in the bathroom.

They are available with an average width of 14-50 inches and height of 12-60 inches. They are efficient at keeping the room temperature stable because of their small size and airtight seal.

Casement windows

They provide better ventilation compared to others and are attached to the frame using one or two hinges. They open outwards in the left or right direction, and you can open any of the two sides or both simultaneously.

There are handles or cranks at the bottom to open it conveniently, and different frame colors and designs are available to match the interior decoration.

The average width is 12-36 inches, and they have an average height of 24-84 inches. They look pleasing and allow more light to warm the bathroom environment, which can minimize mold and bacteria.

Things to consider when selecting standard bathroom windows

It is better to consider some things when selecting the windows for the bathroom because a wrong choice can cause many problems and waste your money.

Bathroom size and location

The choice of a window depends on the size and the space available in the bathroom. Deciding the location for installing it also affects the average size and type of window to select.

You can install small windows if there is not enough space for larger openings, and you have installed a high-power exhaust fan for proper ventilation.

Correct placement can maximize its functionality, such as you can install it above the head height if you have more wall space. In addition, it increases privacy and allows more sunlight into this place.

It will not allow much sunlight if you install it on the backside of the house because the wall shadows restrict the direct light and air entering the room.


It is essential to consider the ventilation required for the bathroom, such as it requires more ventilation if you have a separate bathtub, shower, toilet, and vanity area.

Moreover, more ventilation is needed if you do not have other ventilation sources, such as a powerful exhaust fan or the egress door that opens in the backyard.

Depending on the bathroom size, a larger window can allow more ventilation and airflow in this place.

Bathroom windows can reduce mold and mildew growth, as a more ventilated space has low moisture and humidity level, which causes less mold and bacteria accumulation.


Privacy is the main focus when deciding the size and type of window. It can interrupt your privacy if you install a large one with a plane or transparent glass.

Large windows offer less privacy, as the view inside and outside the bathroom is clearer. In addition, they allow intruders to enter this place through the large openings.

It is better to select textured glass for them, which offers more privacy and restricts the inside view when having a shower or bath.

Professionals recommend selecting glass that is textured, stained, or seeded for better privacy. The large openings will glass covers look stylish and modern in master bathrooms, but the only disadvantage of having them is that they interrupt the privacy of the person.

Building codes

Bathroom windows are usually smaller than the traditional bedroom and living room ones because it usually has less space than the bedroom and living room.

The building codes require a window in every bathroom in the house, no matter how small or large this place, because proper ventilation is essential for all electrical and plumbing connections.

It is better to read all the building codes before selecting the window size, as small places can have small openings, while you can install a standard-size window for a large bathroom.

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