Key Takeaways
- Average casement window sizes range from 2–3 feet wide and 3–6 feet tall.
- Casement windows cost $200–$1,000 on average, with installation adding another $100–$300 per window.
- Most pros advise against DIY installation if you’re inexperienced, as it may void your warranty and lead to costly structural and moisture problems.
Casement windows are hinged on one side, allowing them to swing outward like a door to bring in more ventilation than many other window types. This swinging functionality limits casement window sizes because they need enough clearance to open — most casement windows tend to be narrow and tall, similar to a door. Standard window sizes for casements range from 2–3 feet wide and 3–6 feet tall, with the most common sizes being 2.5 x 4 feet and 2 x 4 feet for kitchens and bathrooms, respectively.
Choosing casement window sizes involves more than just preference. “When choosing window sizes, I advise homeowners to consider three key factors: the room’s natural light needs, the viewing area they want to capture, and the wall space available,” said Robert Wagoner, president and founder of Custom Container Living in Butler, Missouri.
Casement window sizes can also depend on what type of casement window you’re considering and what room you choose to install it in. Read on to learn more about common window sizes, where to install your casement windows, the pros and cons of DIY installation, and how much you should expect to pay for windows and installation.
This site receives compensation from the companies featured in this listing, which may impact where and how products appear. This listing doesn’t feature all companies, products, or offers that may be available.
How To Choose a Casement Window Size
Although standard casement window sizes range from 2–3 feet wide and 3–6 feet tall, some options are more common than others. In general, the most common sizes for casement windows are between 2 x 4 feet and 3 x 5 feet. These standard sizes start at a 2-foot window width and increase in 2-inch increments.
“2.5 x 4 is a go-to for kitchens. Custom sizes exist, but these standards fit most homes and budgets,” said Rich Kingly, CEO of Driveway King in Garwood, New Jersey.
When choosing casement window sizes, consider the type of casement windows you want, the amount of natural light and ventilation you need, your room’s size, and your local building codes. It’s also a good idea to consult your professional installer before deciding on a window size.
Different Types of Casement Windows
The window size you choose will depend on the type of casement windows you’re interested in. Here are some of the most common types of casement windows:
- Single-frame casement windows: These types of casement windows have a single frame with hinges on one side. Some of the most common sizes are 2 x 3 feet, 2 x 4 feet, 3 x 5 feet, and 3 x 6 feet.
- Double-frame windows: Not to be confused with double-hung windows, these casement windows have two frames that meet in the middle, similar to double doors. They’re usually wider than single-frame casements, making larger sizes more common.
- Crank-out casement windows: These casement windows use a crank to push the windows out instead of swinging freely. They feature the same standard sizes as the single- and double-frame models above.
- In-swing casement windows: Unlike traditional casement windows, these windows open inward. These windows need plenty of indoor clearance, so you may need a compact window size of 2 x 4 feet or smaller.
Natural Light and Ventilation
One of the biggest benefits of casement windows is that they allow for significant amounts of natural light and ventilation. However, this can be both a pro and a con, depending on your local climate and how much sun you want in your home.
“Customers should choose window sizes based on what each room is expected to do during the day,” said Alex Smith, a residential/commercial designer and co-owner of Render3DQuick.com in Toronto, Canada. “A good starting point is identifying whether the space needs light, ventilation, or both. In rooms that face north or are shaded for most of the day, larger windows make sense to bring in more daylight. In contrast, rooms that get strong direct sun might need narrower or shorter windows to reduce glare and overheating, while still keeping the space bright,” Smith added.
If you’re concerned about letting in too much light or air, consider a smaller size. You could also install double-pane, triple-pane, or low-emissivity glass models for better energy efficiency. These energy-efficient windows can help insulate your home and keep unwelcome light and heat from entering your house.
Room Size
Room size also plays a role in determining the size of your casement windows. Casement windows are commonly used in smaller rooms, such as kitchens and bathrooms, where space is often limited.
“In a kitchen, you might only have a narrow section of wall between two upper cabinets,” Smith said. “That limits how wide the window can be, so the height becomes more important if you still want daylight and airflow. The same goes for bathrooms, where a window above the toilet or next to a vanity has to respect tile lines and privacy concerns. In both cases, a smaller operable window placed high works well.”
However, if you plan to put a casement window in your bedroom or living room, you’ll likely have more open space. For kitchens and bathrooms, 2 x 4-foot windows should fit well. For bedrooms and living rooms, you may want to choose a size of 3 x 5 feet or larger.
Building Codes
Building codes vary depending on where you live, but most have some kind of egress requirements. Egress windows are windows that double as an emergency exit. Fortunately, casement windows can also act as egress windows. Most local codes require at least one egress window in habitable basements and bedrooms.
However, the size of the egress window requirements will depend on your location. Most governing authorities set the minimum egress window size at 5–6 square feet.
Professional window installers will be well-versed in your local building codes and can help you make the most practical decisions for your home.
Where To Use Casement Windows
Because casement windows fully open up to let in more light and fresh air, they’re a popular choice for areas that need better airflow than a standard single-hung window can provide.
“Casement windows are ideal for kitchens, bathrooms, and bedrooms where both views and ventilation are important,” Wagoner said. Here’s how they shine in each part of the house:
- Kitchens: Casement windows offer maximum airflow, perfect for venting smoke and cooking smells outdoors.
- Bathrooms: Better ventilation and increased natural light can help keep bathrooms looking and smelling fresh for guests.
- Bedrooms: Since casement windows can double as egress windows, placing them in the bedroom can simultaneously offer unobstructed views and a convenient emergency exit.
How Much Do Casement Windows Cost?
Casement window costs vary depending on whether you’re paying for installation as well. If you only want to buy the window itself, prices will be lower. “Casement windows range from $200 to $1,000, with a standard 3 x 5-foot window costing approximately $400–$600. These prices are for the windows only, not including installation,” Wagoner said.
However, custom-size windows will be much more expensive than standard window sizes. “Once you pass 48 inches in any direction or start customizing grille patterns and hardware, prices jump fast,” Smith said. Custom window dimensions smaller than 2 feet wide or larger than 6 feet high will likely cost more than the standard window measurements below, even if the square footage is smaller. Standard sizes are more readily available, making them an affordable option for most homeowners.
Professional installation will also increase costs. “In 2025, expect $100–$300 per window for labor, higher for second-story installs needing scaffolding,” Kingly said. Still, hiring professionals to install your windows could also prevent costly DIY mistakes, so the investment is well worth the money.
The table below shows how much various sizes of casement windows will cost before factoring in installation fees:
| Casement Window Size (Feet) | Average Cost (Windows Only)* |
|---|---|
| 2 x 3 | $260–$360 |
| 2 x 4 | $350–$515 |
| 2 x 5 | $420–$450 |
| 2.5 x 3 | $275–$400 |
| 2.5 x 5 | $460–$480 |
| 3 x 5 | $335–$630 |
DIY Vs. Pro Installation
We recommend that all homeowners consider professional installation for their casement windows. If you try installing your own windows without the proper experience, even with accurate measurements of the window openings, a lot can go wrong.
“Most DIY installations assume the opening is perfect and just slide the new window into place. If the frame is even slightly out of alignment, it will cause water leaks, drafts, cracked drywall, and operational problems over time,” Smith said.
Doing your own window installation can save you roughly $100–$300 per window, but the downsides usually outweigh the benefits. In the worst-case scenario, you’ll spend even more money on window repair costs in the future than you’ll save by doing your own DIY work now.
You may void your window manufacturer’s warranty if you don’t hire a professional.
“While DIY installation might save money initially, I’ve seen too many costly mistakes from improper installation,” Wagoner said. If you’re working on remodeling your home, cheap window replacement is possible, but skimping on professional installation isn’t the best way to save a buck. We recommend investing in high-quality installation to improve your home’s energy efficiency and ensure the job is done correctly.
Are Casement Windows Right for You?
Casement windows are ideal for homeowners who want to maximize ventilation and natural light in their kitchens, bathrooms, and bedrooms. While casement windows are generally more expensive than standard double-hung windows, their swinging design allows in much more of the outdoors.
On the other hand, if you want more airflow but don’t have any large vertical spaces for casement windows, awning windows are a good alternative. These single-hung windows are hinged at the top, allowing them to swing open from the bottom instead of the side. They tend to be longer horizontally than vertically, making them a perfect fit for configurations that may not accommodate casement windows.
If you’re interested in buying casement windows for your home, we recommend reaching out to a local window installer. “Professional installation ensures proper sealing, structural integrity, and warranty protection. A professional can also spot and address any underlying issues that might affect the window’s performance,” Wagoner said.
If you’re eager to get started on your window renovations, start by looking into some of the best window brands to learn more about the windows they offer and their installation services in your area.
