Learning how to measure for valances can feel a bit daunting, but it’s much simpler than you think. A perfect fit boils down to one key choice—inside mount or outside mount—and then taking careful width and length measurements. From there, a few small tweaks based on your chosen valance style will ensure a flawless, professional look.

This guide will walk you through every step, from gathering your tools to handling tricky windows, so you can measure with confidence.

Table of Contents

• Inside Mount vs. Outside Mount: Your First Big Decision
• The Tools You'll Need for Accurate Measurements
• How to Measure for an Outside Mount Valance
• How to Measure for an Inside Mount Valance
• Adjusting Measurements for Different Valance Styles
• Handling Tricky Windows and Common Problems
• Final Checklist: Measure Twice, Order Once
• Frequently Asked Questions

A well-hung valance is the finishing touch that can pull an entire room together. But the secret to that high-end, custom look isn't just the fabric—it's the precision of the measurement. Getting it right the first time saves you the headache of a window treatment that just feels off.

We're here to share our expertise, built from years of helping customers find the perfect fit, to guide you through the process step-by-step.

Inside Mount vs. Outside Mount: Your First Big Decision

Before you even touch a tape measure, you need to decide where your valance will live. Will it fit snugly inside the window frame or hang on the wall outside of it? This choice defines the entire look.

• Inside Mount: This style fits neatly within the window frame for a clean, built-in appearance. It's the perfect choice if you want to showcase beautiful window molding, as the valance won't cover any of the trim.
• Outside Mount: This popular method involves installing the valance on the wall above and outside the window frame. It's our go-to trick for making windows appear larger, hiding less-than-perfect trim, or achieving better light control.

Expert Tip: An outside mount adds dramatic flair and can make a ceiling feel higher. An inside mount offers a tailored, minimalist look. The principles are similar to other home projects, like learning how to measure furniture for a perfect fit.

The Tools You'll Need for Accurate Measurements

Having the right equipment on hand is the first step toward getting professional results. It eliminates guesswork and gives you the confidence to measure accurately.

The single most important tool is a steel tape measure. Avoid using a soft cloth or sewing tape, as they can stretch and sag, leading to incorrect numbers. A rigid steel tape is what the pros use for a reason—it guarantees a straight, true measurement every time.

Here are a few other essentials you'll want to have ready:

• A Sturdy Ladder: Your safety is paramount. Please avoid balancing on a chair when measuring tall windows.
• Pencil and Notepad: Or a notes app on your phone. The key is to write down every measurement immediately—it’s too easy to forget a number!
• A Level: You might be surprised to learn that most window frames aren't perfectly straight. A level is your best friend for ensuring your hardware is installed for a clean, professional look.

Our Favorite Tip: Always measure with a partner if you can, especially for wide windows. One person can hold each end of the tape, ensuring it doesn't dip in the middle. That tiny sag can easily throw off your width by half an inch or more, which is enough to spoil the final look.

How to Measure for an Outside Mount Valance

With an outside mount, your valance hangs on the wall, extending above and beyond the window frame. This is the ideal technique to make a standard window feel larger or to maximize natural light when paired with curtains with valances.

Here’s how to get it right:

• To find the width: Measure the full width of your window, including the trim from one outer edge to the other. Now, add 2 to 4 inches on each side. For a 36-inch window, your final rod width will be between 40 and 44 inches.
• To determine the height: To create the illusion of taller ceilings, install your curtain rod or mounting board 4 to 6 inches above the top of the window frame. This simple move draws the eye upward, making the whole room feel more spacious.

Pro Tip: Hanging a valance high and wide lets the fabric frame the window rather than block it. This not only maximizes the light pouring in but also makes the window itself appear significantly bigger.

How to Measure for an Inside Mount Valance

An inside mount provides that clean, built-in look where the valance fits perfectly inside the window casing. It's a wonderful choice for showing off beautiful, detailed molding, but this method demands precision—there’s no room for error.

Here's something I’ve learned from experience: most window frames aren't perfectly square. To guarantee a snug fit, you must measure the width in three places:

1. First, measure the inside width of the window casing right at the top.
2. Next, take the same measurement in the middle.
3. Finally, measure the width one last time at the bottom.

Always use the narrowest of the three measurements for your final width. This ensures your valance will hang smoothly without bunching up, even if your window frame has slight imperfections. For a deeper dive, our guide on how to measure windows for curtains is a fantastic resource.

Adjusting Measurements for Different Valance Styles

Now, here’s where a little expertise makes all the difference. The style of valance you choose directly impacts your measurements. A lush, gathered valance needs a different approach than a sharp, tailored one.

For Gathered and Rod-Pocket Valances

For this classic style, the key is fullness. To achieve a beautiful, soft bunching effect, you need significantly more fabric than the width of the rod.

• Standard Fullness: Multiply your rod width by 2 to 2.5 times. For a 40-inch rod, you’d want 80 to 100 inches of fabric.
• Extra Fullness: For a truly luxurious gather, multiply the rod width by 3 times.

Insider Tip: If you're using a fabric with a distinct pattern, I always recommend ordering a bit extra. This gives you the wiggle room to perfectly match the pattern at any seams for a high-end, seamless finish.

For Tailored and Box-Pleat Valances

With structured styles like box-pleat valances, the finished width should perfectly match the exact width of your curtain rod or mounting board.

The measurement you absolutely can't forget here is the return. The return is the side piece of the valance that wraps back to the wall, hiding the hardware. Measure from the front face of your rod back to the wall—this depth is typically between 3 and 5 inches.

For Swag and Jabot Valances

Dramatic styles like swags and jabots require planning for elegant drapes and folds.

• The Drop: Measure from the rod down to the lowest point of the swag's curve. A common drop is 14 to 18 inches.
• The Jabot Length: These are the cascading "tails" on the sides. A good guideline is to make them about one-third to one-half of the total window height.

Curious about how these look in real rooms? Browse our guide on popular valance styles for windows for inspiration.

Handling Tricky Windows and Common Problems

Not every window is a perfect rectangle. Quirky layouts like bay windows or corner windows can feel intimidating, but they’re just a series of simple measurements strung together. Knowing how to measure for valances in these situations is where you can really shine.

Measuring for Bay, Bow, and Corner Windows

The key is to treat each pane of glass as a separate window.

• Measure the width of each section individually.
• Measure the angles where the windows connect (typically 135° for a bay window, 90° for a corner).
• Use a special rod connector (a flexible corner or bay window piece) to create one continuous rod for a flowing, uninterrupted look.

For a cohesive design, you'll want one long valance. This means ordering a single piece wide enough to cover the total combined width of all sections, plus extra fabric for fullness if it's a gathered style.

My Personal Experience: When measuring for bay windows, I always add an extra 2 to 4 inches of rod length at each end of the entire bay structure. This ensures the end curtains can fully clear the glass, maximizing light.

Troubleshooting Common Measuring Mistakes

Even with simple windows, a few common slip-ups can happen. Here's what to watch out for:

• Mistake 1: Measuring Only the Glass. Always measure the full width of the window frame or the total area you intend to cover, not just the glass pane.
• Mistake 2: Forgetting Hardware Projection. Your valance needs enough depth, or "return," to clear any underlying blinds or curtain rod brackets. A standard return is 3.5 inches, but you might need up to 6 inches for bulky hardware.
• Mistake 3: Assuming Your Window is Level. Use a level to check the top of your frame. If it's slanted, an outside mount is a better choice as it allows you to create a level visual line above the frame.

Final Checklist: Measure Twice, Order Once

Before you place your order from Joey’z Shopping, let's do one last review. This "measure twice, order once" step is your best defense against the frustration of a return.

Final Verification Steps

• Confirm Mount Style: Does your choice of inside vs. outside mount still feel right for the room's aesthetic?
• Check Fullness Math: For gathered styles, did you account for at least 2x the rod width?
• Account for Hardware: Did you factor in the projection of blinds or the space needed for decorative rod finials?
• Consider Room Scale: Step back and visualize the valance. Does the drop length feel proportional to the window and ceiling height? A standard drop is usually about one-quarter of the window's height.

Getting this right is smart financially. Improper measurements are a huge issue in the window treatment industry, with some sources indicating they contribute to a significant portion of returns. With the growing global market for curtains and blinds, accuracy saves everyone time and money.

Frequently Asked Questions

Here are answers to some of the most common questions we get about valance measurements.

How much wider than the window should a valance be?

The short answer is: 2 to 4 inches wider on each side.

For an outside mount, we recommend extending the valance rod 2 to 4 inches past the window frame on each side. This designer trick makes the window feel grander and helps block light from seeping in around the edges.

What is the standard length for a window valance?

The short answer is: about one-quarter of the total window height.

While there's no single universal standard, most ready-made and custom valances have a length (or "drop") that falls between 10 and 18 inches. This proportion generally looks best.

Do I need to include the curtain rod hardware in my measurements?

The short answer is: Yes, absolutely!

When measuring for an outside mount, your total rod width measurement must include any decorative end pieces, known as finials. Forgetting them is a common mistake that can leave your valance looking too short for the rod.

Now that you're equipped with expert knowledge on how to measure for valances, you’re ready for the fun part. Explore the beautiful and affordable collection of window treatments at Joey'z Shopping and find the perfect valance to complete your room.

Start shopping now and bring your vision to life.