How to Measure for Blackout Curtains – Perfect Sizing Tips

Blackout curtains are trendy window treatments in homes, offices, and hotels. People admire them for their cosy appearance and light-blocking properties. They add privacy and comfort to your spaces. However, these curtains work at their full potential only when you hang them to the right length and width, properly covering your windows.

Correct measurement for blackout window curtains is necessary to achieve a professional look, better insulation, and complete energy efficiency. Poorly fitted curtains look awkward and detract from the visual appeal of your entire interior. Too-short blackout curtains leave gaps and let sunlight into your spaces, undermining the whole purpose. However, extended blackout curtains disturb the entire feel and aesthetics. In this guide, we explain all the steps to measure blackout curtains with precision.

What You Need Before Measuring Your Blackout Curtains

Before you start measuring, gather all the appropriate tools. These are some essential tools that you may require during the process:

• Measuring tape
• Pencil or Marker
• Notepad
• Step stool
• Ladder (if needed)
• Curtain rod or track (installed or planned)

Decide How You Want Your Blackout Curtains to Hang

At the very beginning, decide on the way you want your blackout curtains to appear. It depends on the style and performance you want from your drapes. Based on your aesthetic and functional requirements, decide these things:

Inside Mount vs Outside Mount

If you want enhanced performance, then an outside mount is superior for blackout velvet curtains. The outside mount covers the entire window frame to block any leakage of light. It also makes your small window look larger. However, if you want decorative trim and a modern look, then go for an inside mount. It offers a sleek and built-in look.

Curtain Length or Drop

If you want a clean, tailored look for your blackout curtains, go with floor-kissing length. Your curtains should just touch the floor or hover half an inch above it. However, if you want a dramatic, luxurious look, let your curtains pool 6 to 12 inches on the floor.

How to Measure Window Width for Blackout Curtains

Start your measurement process for blackout drapes by measuring the window width. It is necessary to determine the accurate width of your window curtains to eliminate light leaks and maximise privacy.

Measuring for Curtain Rods

First, measure the window frame width to determine the length of your curtain rod. Use a tape measure to find out the window opening from one end to the other end. Measure from the outside frame to the inside frame. Then extend the total measurements to 6 to 15 inches or 15 to 38 cm on both ends of the window frame. This will allow your blackout drapes to cover the glass, not just the window. Then record the total length in your notebook. This total length is the ideal length of your curtain rod.

Calculate the Curtains Width

Once you get the total width of the curtain rod, multiply it by 2 for soft folds or by 3 for luxurious fullness. The answer will be the total fabric width you need to buy for your blackout window curtain. If you want to hang two panels, then divide the total fabric width by 2 to find the width of each panel.

How to Measure Curtain Length

After finalising the curtain width, now measure the length of your blackout window drapes. First, decide on your drape finish: whether you want sill-length, floor-length, or puddle-length curtains. Then start measuring from the top of the curtain rod or track to the floor or where you want your curtains to end.

If you want still-length curtains for kitchens, then measure from the rod/track top to 1 cm below the window sill. For apron-length office curtains, measure 10 to 15cm below the window sill for a fuller look. However, if you want your blackout curtains to kiss the floor, then measure to the floor and subtract 1 cm. Besides that, if you wish to have puddle-length curtains, then measure to the floor and add 4 to 6 cm.

Measuring Blackout Curtains for Different Window Types

Always take measurements according to your window shape and style for the desired look and functionality.

Standard Windows

For standard windows, ensure the total curtain length is double the rod width for proper coverage. For the desired length, always mount the rod 4 to 6 inches above the window frame.

Bay Windows

For the bay window, measure for each section individually. Take measurements of each window panel separately and use the corner connectors to join the specialised rods.

Sliding Glass Doors or French Doors

For sliding glass doors, always extend the width by 16 to 18 inches on each side. This helps your blackout living room curtains to fully clear the opening and stack back onto the wall without obstructing the view. However, floor-length curtains work well on these types of windows.

5 Common Measuring Mistakes You Should Avoid

These are common mistakes to avoid when measuring for blackout curtains.

1. Measuring the Window Instead of the Rod

Blackout curtains hang from a rod or track, so measure the rod or track length. Never measure the width of the window frame itself to determine your curtains’ width; use the window’s actual width instead to ensure proper coverage.

2. Forgetting the Curtain Fullness

For a uniform and professional appearance, blackout curtains require fullness. Always choose panels that are 2 or 3 times the width of the curtain rod. If you take the exact measurements of the rod, then your curtains will appear flat and dull.

3. Ignoring the Mounting Height

Installing the curtain rod too close to the window frame is a common mistake. To get the desired curtain style, always mount your curtain rod to the correct height. Hang your hotel curtains higher than the window frame, often close to the ceiling, to make your room feel taller. Always decide your rod mounting height before measuring the vertical length of blackout curtains.

4. Ignoring Obstructions

Before measuring, always check for things like radiators, deep window sills, or door handles. They might interfere with how the curtains open or close.

5. Assuming All Windows Are the Same

If you are taking measurements for multiple windows, do not take the exact measurement for all. Measure every single window individually. Even windows in the same room can have slight variations in height and width.

5 Tips for Perfect Blackout Curtain Fit

These are some common tips to get the perfect-sized blackout curtains:

• Measure the width and height from at least three places to account for any unevenness in the window, walls, or floors.

• Always use the sturdy steel tape for measurements to avoid any inaccurate results.

• Always hang your blackout curtain wider on both sides of the window frame to prevent potential light leaks.

• Measure multiple spots, at the top, middle, and bottom, and take the widest measurement for full coverage.

• Ensure panels overlap in the centre for a tighter seal.

Final Thoughts

The secret to flawless blackout curtains is accurate measurements. Correctly measured blackout window drapes provide general comfort, privacy, and light management. When you get the right fullness and proper drop, your curtains look visually appealing, enhancing the look of the whole space. Before making a purchase, follow the above guidelines to measure your curtains properly. A small effort now prevents mistakes later and ensures your curtains fit perfectly, look clean, and work exactly as expected.