Small Bathroom Window Size + Considerations

In addition to energy efficiency, the right bathroom window size will provide incredible ventilation, enhance privacy, and provide ample sunlight in your bathroom. Further, it will add a curb appeal to the entire area. A small bathroom window can be an advantage or a disadvantage, as I have learned from mine. 

The standard size of a small bathroom window size is a width of 107 – 320 cm (42 -126 inches) and a height of 91-198 cm (36 -78 inches). However, you can also find other standard window sizes with widths of 2-6 feet and a height of 2-8 feet.

Depending on the space you have available for a bathroom window, you can have a window as small as you want, although it gets to a point where the size hinders the purpose of having the window in the bathroom.

Small Bathroom Window

How to Select a Bathroom Window Size

With a suitable size, your bathroom window can offer a decent balance between daylighting, privacy, and ventilation. Therefore, consider the following factors when determining the window size for your bathroom:

1. Level of Privacy

A perfect bathroom window size should provide an unquestionable level of privacy. If you are planning to renovate your space and it is necessary to alter the exterior wall, you should position your new bathroom at an angle away from outdoor sight. However, this placement can deprive you of a good view of the outside and minimize the level of natural lighting.

If this is impossible, you can install window treatments to enhance privacy in your bathroom. For instance, you can use sheer curtains to balance privacy and natural light, but it doesn’t work for all designs. If you want a bare bathroom window, consider installing obscure glass designs. 

Stained glass appears attractive in old homes, while frosted glass looks great in modern homes. You can also install opaque films to enhance privacy in your bathroom window. 

Glass blocks can also work well, but they lower the level of ventilation in your bathroom. Further, you can consider installing windows with a lower-emission coating, which is one-way through to hinder people from seeing inside.

2. The Glass Area

Typically, a bigger window allows more natural light to enter the interior. Unless you renovate the exterior wall, you can’t easily remove this window if you only replace existing ones. 

First, you can merge two adjoining windows designed to be fitted to a large opening detached by a removable framing or beam.

You can also invest in windows made from durable frames that enhance durability and strength. For example, composite frames allow manufacturers to produce slimmer frames. 

It may sound like a simple improvement, but minimizing the frame’s thickness can increase the glass area. However, it should not compromise your window’s longevity, performance, and structural firmness.

3. Level of Bathroom Humidity

We know that bathrooms easily acquire a high humidity level, which can lead to mildew and mold development when there’s little ventilation. If mold is left untreated, it can trigger respiratory complications in bathroom users and destroy your bathroom walls. 

Thus, it is imperative to have at least one functional bathroom window. Coupled with an operating exhaust fan, it can help you get rid of excess humidity, heat, and odors. Excessive moisture can also lead to the rusting of most metals, including stainless steel.

You should also consider the efficiency of the window you choose. High humidity levels in your bathroom can condense moisture on the walls. Cold window glasses make condensation form on their surface. Therefore, you’ll require an efficient window under warmer interior glass conditions.

Besides these aspects, there is toilet placement and other fixtures in the bathroom. The window should be positioned to provide maximum light into the bathroom.

Standard Bathroom Window Sizes

Here are the common bathroom window sizes:

1. Sliding Window Sizes

Various sliding window sizes are a convenient option for your bathroom. These options allow you to change the styling and functionality of your space. You can choose among the 2-section and 3-section slider options depending on your preference and the window opening on the wall. 

Sliding window sizes have a higher width than length. Before installing these windows in your bathroom, you should choose a suitable measurement to prevent the compromise of your privacy. Sliding windows have a standard width varying between 91 cm-2.1 m (36-84 inches) and a height between 61 cm-1.5m (24-60 inches).

2. Casement Window Sizes

Casement windows are uncommon replacement windows but provide a high level of ventilation. They are suitable if you live in warm regions, primarily depending on a breeze. 

These windows are fitted with a hinge on one side, allowing you to open them outwards to the left or right. Most people prefer these windows due to their excellent flexibility. Casement windows have a standard width of 35.5-90 cm (14-35.5 inches) and a height of 75 cm-1.95 m (29.5-77.5 inches).

3. Double-hung Window Sizes

These are the most popular and familiar replacement windows in the US. They have a movable sash on their top and base. This allows you to move them in two directions; from the top down and bottom up.

Depending on your bathroom exterior wall size, you can find these windows in various dimensions. Double-hung windows come with a standard width of 61 cm -1.2 m (24 -48 inches) and a height of 0.9 – 1.8 m (36-72 inches).

4. Small Bathroom Window Sizes

Small bathrooms require a perfect-sized window that doesn’t undermine your privacy, ventilation, and energy efficiency. Different small bathroom window sizes come with various designs. 

For instance, you can choose transparent glass bathroom windows to heighten your privacy. Also, you can install textured glass patterns, which can add privacy to your bathroom.

These windows come in various widths and heights. The standard size of a small bathroom window size is a width of 107 – 320 cm (42 -126 inches) and a height of 91-198 cm (36 -78 inches). However, you can also find other standard window sizes with widths of 2-6 feet and a height of 2-8 feet.

Types of Bathroom Windows

To help you choose the best type of bathroom windows for your home, here’s a list of the different options:

1. Transom Bathroom Window

This type of bathroom window is an accent design. You can notice it above a larger window or on top of a door. However, you can also use it as a stand-alone window for your bathroom.

Transom bathroom windows can guarantee you a high level of privacy and increase the light penetration in your bathroom. These windows are available at an affordable price. When installing this design, ensure you position them at a high level to achieve your desired privacy.

2. Hopper Bathroom Window

They’re almost similar to transom windows. However, hopper windows open downwards. This window type is perfect if your bathroom experiences high moisture and humidity after a hot shower. 

Opening these windows after a shower can help you acquire natural ventilation in your bathroom. Like the transom windows, you should position these windows at a higher level to safeguard your bathroom’s privacy.

3. Shutter Bathroom Window

Also known as plantation shutters or shutter-style blinds, shutter windows are unique bathroom windows for multiple reasons. First, these windows allow you to control the amount of natural light entering your bathroom with various levels of privacy.

They also allow rays of sunlight to penetrate in, releasing the air out when you flip the shutters. Later, you can shut them down to enjoy your privacy.

Shutter bathroom windows are also advantageous since they can improve your bathroom interior and add an elegant central point, depending on your material. 

Faux wood is the most common choice for shutter bathroom windows, offering an inexpensive style. This material is also resistant to moisture, minimizing the risk of future damage.

4. Glass Block Bathroom Window

Glass block bathroom windows allow plenty of sunlight to light up your bathroom without compromising your privacy. Adding these windows in your dark bathroom can illuminate your entire space. These windows are flexible, so you can install them according to your preference. You can install glass blocks or standard-sized windows to cover your bathroom wall.

You can get these windows pre-shaped to fit your standard bathroom window size or as a single block that can be cut to fit your small bathroom window size. However, these windows are disadvantageous since you cannot open them to provide natural light. 

If your bathroom suffers from extreme condensation, it is better to have moisture-absorbing plants, a bathroom fan, or combine glass-block bathroom windows with another design that will provide natural ventilation. 

5. Slider Bathroom Window

Slider bathroom windows are among the most common windows due to their unique affordability. Once opened, they can supply natural lighting and ventilation in your bathroom, depending on the side. These windows require an easy installation. Amazingly, they come in a simple style suitable for various bathroom styles and sizes.

However, when installing these windows, you’ll require weatherstripping between noticeable gaps and sashes. Otherwise, your window can quickly freeze during winter. Nonetheless, these windows will provide excellent energy efficiency when combined with weatherstripping.

6. Skylight Bathroom Window

Skylight bathroom windows are a unique luxurious design. They are cut through your bathroom roof and ceiling to allow the sunlight to hit on your head during the day or allow you to watch the skylight when showering at night.

These windows are typically fitted above the shower area, which provides incredible natural light in the bathroom and a genuine experience that allows you to relax during the shower. However, this type of bathroom window is an expensive option that you can choose as a luxury.


Choosing the standard window size for your bathroom will cater to your privacy while enhancing ventilation, a suitable level of humidity, light penetration, and energy efficiency. Installing the right bathroom window will also increase your bathroom’s appearance and cater to your respiratory health. 

Thankfully, I have discussed various bathroom window sizes and styles. Each type comes with its benefits and drawbacks. You can now confidently choose your subsequent small bathroom window size for window replacement.

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