How to Measure a Window for Curtains

Measuring the width of a window for curtain size

The Spruce / Meg MacDonald

Project Overview
  • Working Time: 15 - 20 mins
  • Total Time: 15 - 20 mins
  • Skill Level: Beginner

Hanging curtains in your home is one of the most effective things you can do to enhance the look of your interior. Curtains can filter or fully block light, add privacy to a room, dampen echo, and, if properly mounted, make your interior look bigger than it actually is.

The key to properly mounting curtains is understanding how to measure your windows beforehand, then buying appropriately sized curtains and curtain rods. Follow the steps below to accurately measure your windows and buy the right curtains every time.

What You'll Need

Equipment / Tools

  • Measuring tape
  • Pencil
  • Level
  • Step ladder


Materials needed for measuring a window for curtains

The Spruce / Meg MacDonald

How to Determine Curtain Rod Width

Purchasing the correct curtain rod is crucial to hanging your curtains properly. While you likely assumed the curtain rod must be at least as wide as the window itself, it may be harder to gauge just how wide the curtain rod should be.

  1. Measure Window Width

    Measure the window from side to side, including trim if present.

    Measuring the outer width of the window

    The Spruce / Meg MacDonald

  2. Add Space for Curtains

    When you draw the curtains to the side, if you haven't accounted for the space the bunched curtains will take up when choosing your curtain rod length, they'll block the light of the window. Add 16 to 24 inches to your measurement, then choose a rod that extends to your determined width. This will make the window seem larger by revealing as much light as possible when the curtains are opened.


    Thicker curtains may require more space on the sides, as they don't bunch as tightly as thinner curtains. Also, keep in mind that larger windows requiring more than two panels will need more space for the additional panels to bunch.

    Adding extra inches to accommodate the curtains

    The Spruce / Meg MacDonald

How to Measure for Curtain Width

It may seem simple, but there are a few things to keep in mind when determining the width of curtains needed to cover your window.

  1. Measure Window Width

    Measure the width of the window, including any trim present.

    Measuring the window width

    The Spruce / Meg MacDonald

  2. Factor in Rod Spacing

    Factor in the amount of space you chose to extend the rod past the window—then add that to the overall width of the curtains.

    Factoring in rod spacing

    The Spruce / Meg MacDonald

  3. Factor in Desired Looks

    Ask yourself what you want the curtains to look like when fully closed. If you want them to still look bunched and textural, opt for wider curtain panels. If you want them to look sleek and straight, buy curtains that perfectly match your determined width.

    Factoring in how the curtains should look when fully closed

    The Spruce / Meg MacDonald


    If you're mounting curtains on a wide window or a set of glass doors, consider opting for more than two curtain panels. This will increase the number of curtain options available to you.

How to Measure for Curtain Length

Arguably, the trickiest part of measuring a window for curtains is determining the length of curtains you should buy. This is because it's hard to know just how high to hang the curtains and how the curtains should meet the floor. While, in the end, this completely comes down to preference, there are a few designer rules for curtain length.

  1. Determine Curtain Height

    The biggest no-no in hanging curtains is placing the rod too close to the top of the window. This makes the room look small and squatty by making the ceilings appear shorter. On the other hand, increasing the distance between the curtain rod and the window can make the room appear larger (within reason).

    If you have standard 8-foot ceilings, take the curtain rod all the way to the ceiling. If your ceilings have crown molding, mount the rod just below the crown mold.

    If you have high ceilings, choose a spot 12 to 14 inches above the top of the window to mount your curtain rod.

    Using a tape measure to determine curtain height

    The Spruce / Meg MacDonald

  2. Determine Curtain Length

    Once you've determined where to mount your curtain rod, you can choose how long curtains to buy. This will be determined by how you prefer for the curtains to meet the floor. Choose one of the following:

    1. Kiss: The kiss look is when the bottom of the curtain barely touches or "kisses" the floor. To achieve this look, use the exact distance between the rod and the floor for your measurement.
    2. Float: The float look is when the bottom of the curtain floats just above the floor. To achieve this look, subtract 3/8 to 1/2 inches from your height measurement.
    3. Puddle: The puddle look is when curtains are intentionally left longer to puddle on the ground, which is considered a more formal look. A standard puddle is achieved by adding at least 6 to 16 inches of fabric to the overall length, but there are varying degrees of puddling, so choose what you like best.
    4. Break Puddle: The break puddle look is one of the most common puddle looks. A break puddle is achieved by adding 1/2 to 1 inch of fabric, just so the curtains touch and break at the floor. This is a great middle-ground for those that like the appearance of the puddle look but the functionality of the float and kiss looks.
    Determining curtain length
    Kiss curtain length

    The Spruce / Meg MacDonald

    Float curtain length
    Float curtain length

    The Spruce / Meg MacDonald

    Puddle curtain length
    Puddle curtain length

    The Spruce / Meg MacDonald

    Break puddle curtain length
    Break puddle curtain length

    The Spruce / Meg MacDonald


    While beautiful, puddle curtains can be a tripping hazard for children and elderly individuals.

How to Guarantee Accurate Curtain Measurements

While these measuring tips are a great start, every type of curtain will hang differently on different types of rods. Even if you've measured perfectly, curtains can lose a couple of inches once mounted on a rod, causing them to float rather than kiss the floor. If you've already mounted your curtain rod, this will require you to reposition the rod. If possible, call upon a friend for help. With the curtain mounted on the rod, have a friend hold the rod against the wall to determine where it should be mounted.