How to Measure Your Window For Blackout Curtains: Step by Step

How to Measure Your Window For Blackout Curtains: Step by Step

Picture this: it's finally bedtime after a long, exhausting day of juggling work, chores, and caring for your children. You snuggle into your sheets, closing your eyes for the peaceful sleep you've been craving. Just as you start to drift off, a stray beam of light from the streetlamp outside pierces through your window, streaking across your eyelids. You're jerked awake, your much-needed rest disrupted by this unwelcome intruder: light pollution.

Unfortunately, this scenario is all too familiar for many of us, particularly mothers who find that a good night's sleep is essential but elusive. That's where blackout curtains can be a game changer, offering a simple yet effective solution to controlling light pollution in your home. These curtains not only enhance your sleep quality and comfort but also add an aesthetic touch to your interior decor.

In this blog post, we will provide a comprehensive guide on how to measure your windows for blackout curtains. Armed with this knowledge, you'll be able to create the perfect sleep environment for you and your family.

room with curtains in it

The Importance of Proper Measurement

Getting the right measurements for your blackout curtains is crucial for a couple of reasons. First, if the curtains are too small, they might not completely cover the window, allowing unwanted light to seep into the room. On the other hand, curtains that are excessively large can look untidy and disproportionate to your window, ruining the aesthetic appeal of your room.

Another aspect to consider is the concept of "oversizing." Blackout curtains are typically designed to be larger than the window they cover. This extra size ensures complete coverage and maximum light blockage, enhancing the effectiveness of the curtains.

woman preparing to hang curtains

Getting Set Up

Before you start measuring, make sure you have the necessary tools at hand. Here's a checklist:

  1. Measuring Tape: A retractable steel measuring tape is ideal for accuracy.
  2. Step Ladder: If your windows are high, you might need a step ladder to reach the top.
  3. Pen and Paper: To note down the measurements.
  4. Helper: If possible, having a second person can make the process easier and safer.

While measuring, always prioritize safety. Ensure your step ladder is sturdy and positioned correctly. If you're measuring a high window, having a helper can prevent accidents and ensure more accurate measurements.

curtains hanging in window

How Much Bigger Should Blackout Curtains Be Than My Window?

As a general rule of thumb, your blackout curtains should be wider and longer than your actual window. This is to ensure full coverage and prevent light leakage around the edges. Typically, your curtain's width should be 1.5 to 2 times the width of your window, while the length should be about 6 to 12 inches longer than the window.

However, these dimensions can be customized based on your specific needs. For example, a nursery might require even more coverage to ensure complete darkness for your baby's optimal sleep.

curtains hanging in window

Step by Step Guide to Measuring Your Window

Here's a simple guide to help you measure your windows for blackout 


  1. Measure the Width: Use your measuring tape to measure the width of your window from one side of the frame to the other. Record this measurement. Remember, you'll need your curtain's width to be 1.5 to 2 times this measurement for full coverage.

  2. Measure the Height: Next, measure the height of your window from the top of the frame to the windowsill or the floor, depending on where you want your curtain to end. Don't forget to add an extra 6 to 12 inches to this measurement to account for the curtain rod and to ensure your curtain sufficiently covers your window.

  3. Measure the Curtain Rod: If you already have a curtain rod installed, measure its width as well. This measurement can help you ensure that your new blackout curtains will fit perfectly on the rod. If you don't have a rod installed yet, plan for it to extend at least 3 to 6 inches on either side of your window frame to prevent light leakage around the edges.

  4. Repeat: It's always a good idea to measure twice to confirm your measurements.

For a clearer understanding, consider referring to diagrams or photos available online. These visual aids can make the process more straightforward and help you avoid common measurement errors.

little girl sleeping in bed


Getting a good night's sleep is not a luxury—it's a necessity for our physical and mental well-being. And one major step towards achieving this is by controlling the light in our sleep environment, which is where blackout curtains come in. They not only offer an effective solution to light pollution but also add a touch of elegance to your room decor. However, to ensure these curtains serve their purpose optimally, correct measurement is crucial.

To make it easier, consider investing in the most recommended blackout curtain by sleep specialists in North America. Use the code WELCOME10 for $10 off your purchase. Start your journey towards a better sleep environment today.

Back to blog

Experience 100% Blackout Fabric