How to Measure for Curtains

How to Measure for Curtains

Leaving your windows naked and bare means you’re missing out on a big interior design opportunity. The right curtain measurements provide privacy, filter sunlight, and add warmth while bringing style to your home. Before you choose the perfect drapes for your space, check out our tips on how to measure curtains.


Determine Mounting Technique

Semi-sheer curtains mounted on curtain rod

When you begin curtain measurements, it’s important to decide whether you want to mount them outside or inside of the window frame. Each mounting style offers a completely different aesthetic.

Outside Mount Curtains

The outside mount is the most common mounting style for hanging curtains. When curtains are mounted outside, the rod is secured to the wall outside of the window frame. Outside-mount curtains can give the illusion of a larger window, provide full coverage to block out natural light, and create a more luxurious look.

Inside Mount Curtains

While not as common, inside-mount curtains are another mounting option that will provide a specific look. Inside mount refers to a curtain rod that is secured inside the window frame, creating a more streamlined appearance. Inside-mount curtains don’t completely block out light, but they still provide plenty of privacy and offer a modern, minimalist look.


Determine Rod Length

Semi-sheer beige curtains on medium length curtain rod

Before you measure your window for width, it’s best to choose the length of your curtain rod. Curtain rods are typically extended 3 to 6 inches past a window frame. However, because rods can be installed either inside, below, or above trim mount, determining where you install your rod affects the length. As for diameter, you’ll want a curtain rod that’s at least an inch thick for the strength to avoid bowing in the middle.

Inside Trim Mount

For streamlined, tailored window treatments, suspend curtains from within the window frame. Opt for curtain rods with protective end caps and an expandable design for a snug fit. Window treatments for this modern style should only be about as wide as the interior of the window or slightly wider if you want a gathered look.

Below Trim Mount

If the top of your window frame has beautiful molding, consider curtain rod placement just below the trim. This is a great way to showcase the craftsmanship of your molding while adding privacy and style to your windows. Look for a curtain rod that reaches at least 3 to 5 inches beyond the width of the window on either side for a full look.

Above Trim Mount

The ideal placement of curtain rods is typically about 6-12 inches above your window frame. However, it really depends on the available space between the top of your window and the ceiling, and the overall aesthetic you’re going for. Curtains can be hung as high as 20 inches above the window frame to create an elongated appearance. The higher and wider your curtain rod placement, the larger your window will appear.


To learn more about how to measure for curtain rods, read our Tips on Buying Curtain Rods guide.


Choose Your Curtain Length

Floor length rod pocket curtains

Next, you’ll want to consider the interior design style you hope to achieve, which will determine the right length of curtains. There are three ways to hang your curtains, depending on what look you prefer.

Above Sill

Curtains that hang above the sill typically sit 1 cm above the windowsill.

Below Sill

This requires curtains to end roughly 15 cm below the windowsill.

Floor Length

Floor length depends on what style you prefer, but standard curtain lengths usually end 1 cm above the floor.


Measure for Width

Grey blackout curtains with tiebacks in bedroom

Curtain widths should typically be about 1 1/2 to 3 times the final width measurement of your window. However, the fullness you choose will ultimately define the style you want to achieve. Fuller curtains lend a richer feel to your windows while curtains with a shorter width create a more tailored look.


Keep in mind that window panels are usually listed as separate items, so check if your curtains come in a pair or whether you’ll have to buy it a partner. If the curtains come separately, double the curtain panel’s listed width. You can use a tablecloth or blanket to compare full sizes.


Measure for Length

Traditional living room with floor-length curtains

Window treatments are most commonly measured width by length, where length is the distance from the rod pocket to the very bottom of the panel. Valances, which traditionally only take up the top one-quarter of the window, are also measured width by length. To learn more about hanging valances, read our guide on How to Hang a Valance and Curtains.


Curtain lengths will ultimately depend on your hanging method and desired look. To visualize your curtain measurements, place the measuring tape at the top of the window frame or in the top inside corner and measure down to your desired length. For a higher curtain placement, measure up from the top window framhow to measure for curtain panelse 20 inches to achieve an elongated appearance.


If you have a pair of bay windows and want to measure for the perfect pair of curtains, take a look at our guide on How to Measure Curtains for Bay Windows.


Now that we’ve laid out how to measure for curtain panels, you can spend more time choosing the best curtains for your home. To learn more about curtains, read our Curtain Buying Guide. Or start shopping curtains on, where every order comes with free shipping*.

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