We understand that selecting the appropriate curtain measurements, whether for blackout curtains or sheer curtains, can be daunting. Determining the appropriate length, whether to measure from the top of the window or curtain rod, and the appropriate width can all be overwhelming. How long should the length be? Should I measure from the top of the window or the top of the curtain rod? And how about the width? All of these questions can be overwhelming.

This is why Deconovo design experts teamed up to compile a simple guide to help you choose the right curtain sizes that best fit your style choice.

The 3 Basic Elements of Calculating your Curtain Measurement

Curtains are a piece of decorative textile that dresses your windows. They add style to your interior while bringing you a set of features such as light-blocking, thermal insulation, soundproofing and privacy.

When it comes to measurements, choosing the right curtain length and width can make or break your decor.

That is why we always recommend figuring out your drapes size first before hunting for the perfect window treatment design. Otherwise, you might find yourself lost in the sea of choices available.

Choosing the right size comes down to three essential steps:

  • Step 1: Decide on your Curtain Length (Style-Based Choice)
  • Step 2: Figure out your window width
  • Step 3: Decide how many panels to hang

    Please keep in mind that the size of the curtains is always indicated for open flat curtains.

    That is why, in the width section, you need to take into consideration the waving effect when choosing your curtain width.

    Step 1: Decide on your Curtain Length (Style-Based Choice)

    When it comes to the length of your curtains, it will mostly depend on your preferences.

    You will need to decide if you want your curtain to hang on the floor, at the sill of the window or a bit lower.

    The choice you will make; will define how you need to measure your window length.

    Image of 3 curtains measure with different hanging style

    Once your curtain length style is chosen. You can go ahead and start measuring your window.

    Style 1: Floor Length Hanging

    If you want a floor hanging curtain, measure the distance from the curtain's top to the floor.

    The total length measured will be equal to your curtain length.

    image of a curtain and a description on how to choose the measure

    Tip: Reduce the length measured by 1 cm, so your curtain will hang right above the floor. This will enhance the curtain waves and create a clean look.

    Style 2: Below Sill Hanging

    Measure the distance from the top of the curtain until the desired length below the sill. The length measured will be equal to your curtain length.

    image of a curtain showing length measurement

    Style 3: Window Sill Hanging
    This is a go-to if you want to free space below the window. Usually, rooms with wall radiators or desk spaces will want the curtain not to obstruct the way.

    In this case, you will measure your window length from the top of the curtain rod to the bottom of the windowimage of curtain length measure

    Tip: For more fullness, you can choose to add 1-2 cm to hang curtains slightly below the sill.

    Step 2: Measure your Window Width:

    By measuring the window width, we mean the total width, including the curtain rod. A common mistake people make is to exclude the curtain rod length while selecting their curtain size. This lead to the curtain not having this wave drapes that make them so beautiful.

    The general rule is that your curtain width should be x1.5 to x2 the size of your window width. It means that if your window width is 100 cm, the curtain width should be 150 cm to 200 cm to ensure your drapes will have a beautiful hang (wave effect).

    To figure out your window width, you will need to measure your curtain rod's total length without measuring the finals. Then, multiply it by x1.5 to x2, to obtain the total curtain width you need.

    image of curtain showing how to measure the width

    But wait, I don’t have a curtain rod yet, how to measure my window width?

    In this case, we suggest you measure your window width, including the frame and add 6 inches each side. That is because most likely your curtain rod will be longer than your window from each side.

    Step 3: Decide how many panels you will hang on your window

    By now, you already know exactly how wide and long your curtain should be. The next step is to figure out the number of panels you want for your window. 

    If you want to go for one panel only, then the curtain's width and length would equal the measurement you've got. For a set of curtains, you will need to divide the width by 2.

    For instance, if the width you need is 150 inches, you can either choose a 150 inches' curtain or a set of curtains, each measuring 75 inches.

    image of beige curtains in a living room

    (Note: Actual customer image)

    Common Mistakes when Choosing Curtain Measurements?

    Although choosing curtain length and width is easy, many still commit mistakes over and over again. It is important to select the right curtain size. Otherwise, you will badly influence your room decor. Here are the top common mistakes:

    Mistake 1: Rod Placement

    This is the most common mistake that causes the room to look shorter. When hanging your rods, make sure they are at a proper height. If hung too low, the room will not look good.

    Always hang your rod high so the sightline will be lifted and the ceiling will look taller.

    Mistake 2: Short Curtains
    Always measure your length before you purchase your curtains. A common pitfall concerning short curtains is that people don't include the space between the rod and the window resulting in a short curtain.

    This is especially bad if you hang your curtains on a french door or balcony because you have light coming from the bottom.

    Mistake 3: Curtain Panels aren't wide enough

    This is also a common mistake but the worst to make. If you buy curtains not wide enough, they will look plain and won't have that beautiful drape. So you must always factor more width to ensure a beautiful wave style.


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