Standard Bay Window Sizes and How to Choose the Right One

A bay window can be a beautiful and functional addition to your home, giving you space for a cozy reading nook or a light-filled dining area. But how can you know what bay window size is right for your home? Before you start your project, make sure to determine what size will work best so you can begin enjoying your bright, spacious new window.

What Are Standard Bay Window Sizes?

Bay windows are a combination of three windows, one center window running parallel to the wall and two flanking windows set at an angle outward from your home. These windows come in a wide range of sizes, styles, and configurations, so there’s almost no limit to what size your bay window can be. There are, however, a number of standard window sizes that you can purchase already configured, eliminating the need for costly customization.

Bay Window Size by Type

Canted Bay Window

Canted bay windows are the traditional bay windows you’re probably used to seeing, with three windows making half a hexagon extending outward from the house. Canted bay windows are often used in living and dining rooms on the first floor. They can vary in size but are typically at least 4 feet wide and 3 feet 6 inches high or larger.

Box Bay Window

A box bay window is a popular choice for kitchens or smaller areas. These windows also consist of three windows, but all at right angles to each other, forming a box shape extending out. Box bay windows are smaller than most other bay windows, often smaller than 3 feet 6 inches in both width and height.

Circle Bay Window

Circle bay windows are less common than other types of bay windows and are set at less of an angle, giving them a more rounded shape. These windows are often larger than other styles and can measure anywhere up to 10 feet wide and 8 feet high or more. 

How to Measure the Right Size Bay Window

Bay windows can be a little more complicated to measure than other windows since you’re dealing with not only width and height but also depth and angles. To find the right size bay window, you’ll want to measure the rough window opening’s width and height, allowing for the manufacturer’s required spacing between the window and the rough opening. The window depth will be the measurement from the window opening to the front panel.

The three windows that make up a bay window configuration will likely be two different sizes—a large central window and two smaller windows, one on each side. Measure each window’s width and height for accurate measuring. Most traditional bay windows are set at a 30- or 45-degree angle—you can check this with the manufacturer if you don’t want to bring out the protractor.

Factors That Influence Bay Window Size

Budget

When it comes to bay windows, one of the most important factors is your budget. These windows are pricier than other types of windows, with the cost of a bay window averaging between $950 and $7500. The larger the bay window, the more you can expect to spend. Familiarize yourself with all the benefits and drawbacks of bay windows before investing.

Wall Space

The amount of available space will be a determining factor for the size of your bay window. Larger rooms on the first floor, like living rooms and dining rooms, can accommodate larger bay windows, while rooms with less available wall space, like kitchens or rooms on upper floors, will need smaller bay windows.

Building Codes

Your local building codes may also restrict the size of the bay window you can install, although these regulations usually deal with the allowable depth of bay windows and necessary structural support rather than the width or height. Be sure you are aware of any applicable codes.

Structural Support

Because bay windows extend out from your home, the wall and window will need additional structural support in order to prevent sagging or damage to your home. Larger bay windows will require more extensive support. You may find that your home can only accommodate a bay window up to a certain size without requiring extensive work to add support.

What To Do if You Have the Wrong Size Bay Window

Choosing the wrong size bay window for your home can drastically increase the cost and time of your window replacement project. You may want to hire a local window replacement company to tackle the job. They can help you choose the right size bay window for the available space, your budget, and the structural specifics of your home. Once you have the right size bay window installed, you can start enjoying your home’s bright new feature to the fullest.