How to Make Your Room Pitch Black at Night

If you find it hard to fall asleep or to stay asleep through the night, one of the most basic fixes you should make is to sleep in complete darkness. Here's how to make your room pitch black.

It all starts with your window dressing.

Choosing the Right Blackout Blinds and Curtains

The best way to make your room dark is with a combination of inside-mounted blackout blinds or shades and outside-mounted blackout curtains. “Inside” means the shades are mounted inside the window frame and “outside” means the curtain rod is mounted on the wall several inches outside the window frame. The word “blackout” is very important because these products also have “light filtering” and “room darkening” versions that are less effective.

Combining outside-mounted blackout curtains with inside-mounted blackout blinds.
The curtains hang from a rod that is mounted to the wall, approximately 6 inches above the top of the window frame and 6 inches outside the outer side of the window frame. The blackout cellular shades hang from the top of the inside of the window frame and extend slightly less than the complete width of the inside of the window frame.

There are two reasons you need a combination of inside-mounted and outside-mounted products. First, even the “blackout” versions do not block 100% of the light, so doubling up most of the area makes the light-blocking more effective. Second, inside-mounted products allow light to leak around the inside edges of the window frame while outside-mounted curtains allow light to leak through the middle where they meet. If you have both, the inside-mounted shades block the light in the middle and the outside-mounted curtains block the light at the edges of the window frame.

Here's a video I made showing you why both products are important:

You may be wondering if you can simply use outside-mounted blackout blinds or shades as a single product. I don't recommend this. Although they cover both the middle and edges, they create a gap several inches deep between the window and the blinds, and a smaller gap outside the window frame between the wall and the blinds. This will allow plenty of light to leak out the top, bottom, and sides.

Ordering Your Shades

Cellular shades are better for blocking out light than blinds, but if you also have curtains I don't think it makes much of a difference. I would avoid roller shades because they are more likely to curl up and become less effective with time. If you get cellular shades, I'd get cordless ones. They are a little harder to install than corded ones, but unless you invest a lot of money in high-end products the cord is likely to become dysfunctional after a year in my experience.

You can buy blackout shades at Home Depot and have them cut to the right width in the store, or you can order them on Amazon, where the selection is better.

Before ordering, measure the inside dimensions of your window frame. Here's a quick video I made on how to take the measurements:

You want the width of the shade to be a quarter to a half inch narrower than the width of your window frame, and you want the length to be at least as long as the inside height of the window frame but not much longer. Dimensions are listed online with the width as the first number and the height as the second number. Be careful to read the description, because some brands give you the width of your window frame and adjust it down a half inch for you, and some brands give you the width of their shade and tell you to get it slightly shorter than your window frame. For the height, get the shortest height you can that is longer than your window is tall.

For example, let's say your window frame is 26″ wide and 54″ tall on the inside, and you want to order the Calyx Interiors Honeycomb Cellular Blackout Shade. The description tells you to order at least a 1/4″ shorter than the width of your frame, so you would get the 25.5″ option because it is the smallest increment below 26″ you can order. The height options are 48″, 60″, and 72″, so you'd order 60″ because 48″ is too short and 72″ is unnecessarily long. So, you'd order the 25.5″ x 60″ option.

Ordering Your Curtains

Bed Bath and Beyond has a better selection of blackout curtains than Amazon. For aesthetics, you want two panels even if your window is narrow enough to be covered by one panel. For many windows, you would need two panels simply to cover the full width. Other than making sure that your panels, when combined, are large enough to cover the entire outside dimensions of your window frame, the rest is personal style. You might prefer they go to the floor, or you might prefer they end a few inches below the bottom of your window sill. Choose a style you like and make sure to get at least a rod so you can hang it. Depending on how pretty you like your windows, you may want finials, holdbacks, and a double rod system so you can hang lace curtains on the lower rod and blackout curtains on the higher rod.

Installing Your Shades and Curtains

Google is rich with tutorials of how to install these products. Use phrases like “inside mount” and “outside mount” when searching, and make sure you have everything you need (an electric screw gun makes it much easier, and a pencil is a great thing that I never seem to have around) before you get started.

Make sure the inside-mounted blinds or shades cover as much of the inside of the window frame as possible, and that the outside-mounted curtains extend a few inches beyond the outside of the window frame on the top, left, and right, and stretch at least below the bottom of the window sill on the bottom.

Using Curtains With an Air Conditioner

All of this becomes complicated if you're trying to black out a window with an AC because you can't let the shade or curtain block the air flow from it. If the AC is installed in the window, you simply need to order your inside-mounted shades at a shorter length that covers the window frame above the AC.

It's the curtains that are difficult. You could have them hemmed to end just above the AC, but it would ruin the daytime aesthetics to have them so short.

I used to roll the curtains up to hang above the AC with clothespins, but I've since found a better way:

  • Buy one or two packs of Velcro.
  • Buy one bottle of fabric glue. The Velcro does have adhesive on the back but it's not strong enough for this purpose.
  • Measure where you'd need to place the Velcro on the back outside edge of your curtains to fold it to just the height needed to sit above the air conditioner.
  • Follow the instructions on the fabric glue to fasten the Velcro into that position. You'll need a furry side and a prickly side to cling to one another, one at the bottom of the back outside edge of the curtain and one on the same edge where the bottom will attach in the fully folded position.

At a minimum, do this on the outside back edge of each panel. If you find that the curtain sags in the middle when folded, you might want to put additional Velcro strips in the middle of the back of the curtain to prevent that. If you can't stop it from sagging, it may make it harder to overlap the curtains in the middle and you may still need clothespins to join them together in the middle.

Here's a video showing how I solved this problem for my window:

Tack the Curtains When Sleeping If Necessary

If the curtains hang freely, you should achieve complete darkness at night. If, however, you need to make adjustments such as those described above for an AC, they may hang in a way that fails to completely block light from slipping through the sides of the window. If needed, you can fix this by pinning the curtains to the outside of the window frame with thumb tacks before you sleep.

Unplug and Cover Up Electronics

Unplug whatever can be unplugged, and use electrical tape to cover up any lights that can't be unplugged (for example, on your AC if you are using one).

Block Light From Other Rooms

Ideally, simply closing your bedroom door is enough to make your room pitch black if you've done everything else listed above. However, you might find light slipping into your room through the door cracks. If you do, you need to either block the light at its source by following these recommendations for the next room over, or you need to hang a blackout curtain around the outside of the frame of your bedroom door.

Get a Sleep Mask

If your room is anything less than pitch black, a sleep mask can help block the residual light. It can also help you sleep later in the morning when it gets bright enough outside your room for the light to start penetrating the fortress you just created. I used to use a flat sleep mask, but have recently switched to the Lonfrote Deep Molded Sleep Mask. It cups around your eyes and blocks residual light around the edges that a flat sleep mask cannot block. At $9.99, it's a highly cost-effective way to achieve superior light-blocking.

What's In My Windows

Here's what's in my windows:

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How Do You Keep It Dark?

Were these ideas helpful? Do you have any better ideas? Let me know in the comments!

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  1. Earlier in these comments you will find a question I posted in 2017, wondering how I could have a completely dark room with fresh air coming in also. My casement windows make that very difficult. I found the solution (or rather my husband did), so want to share it here. I use blackout blinds on tracks that cover the window, but if I open the windows, that means either light coming from the opening, and/or breezes blowing the blinds off their tracks, and light coming in as well (also the blinds get ruined). Here’s the solution: I still use the same blackout blinds, but, my husband took two pieces of metal, each one 1/2 the width of the window, to a welding place that could mold them into a shape that has one part resting on the windowsill, and the other sticking straight up across the lower part of the window. Each part is about 5-6″. You put them in the window so that the two pieces fit together in the center. The casement windows can be open as much as we want, as long as it’s not too windy out–we actually get quite a bit of fresh air with only opening them a small amount, as the windows are fairly tall. Then I pull the blackout blinds over the section the sticks up along the window. Because the metal things are black, they absorb any light that comes through, as well as blocking it. The metal section is pushed back flat against the window so the blinds fit right over it. I lower the blinds only about two inches over the metal, and voila! Completely dark and fresh air too! I wish I could have added a picture here, because this is hard to describe, but hopefully you can figure it out if you want to try it too.

    1. Sounds cool! Perhaps you could upload some photos to or a similar service and then share the link with us?

  2. I recently visited Thailand and am kicking myself for not bringing back a standard curtain hanging piece I saw there. The inside edge of one side of a pair of blackout curtains is hung with a special overlap piece. The hanger protudes outward slightly so that the curtain hanging from it can slightly overlap the curtain next to it. It eliminates the crack in the middle! This should be standard everywhere!

  3. I use a single, outside mount blackout blind. It was okay, but not great due to light leaking through the sides. I realized the sheetrock framing the window had a metal corner piece, called a bead I believe. I then simply used two magnets on each side of the blind to hold the fabric against the wall. I have to place them every evening after closing the blind. Works great. Minimal light filters through.

  4. Hi Chris,
    I love this article! I’ve been experimenting with low blue lights and dark nights now for several years, and have come to many of the same conclusions as you have. I like the technique of curtains layered over shades. I’ll have to try that. One problem I have been unable to solve: I like to sleep in a completely dark room, and, I like fresh air at night. I also like quiet–but that i can usually solve with earplugs. But I have not found a way to have both a dark room and a window open for fresh air! Do you have any ideas? (I don’t like air conditioners, for a variety of reasons). Thanks!

  5. Fantastic info! Personally, I have to worry more about blocking light coming from IN my house (I live in the woods, but my family tends to stay up later than me and so the light from the living room peeks through my door) but loved the article nonetheless! 🙂

  6. Thanks Chris, this is a very important practical point that is often left uncovered in health practitioners writing about insomnia online (many of whom live in California and have probably never even seen a window A/C unit). I have always found that the American-style A/C window units I installed in my Brooklyn apartments were the fatal flaw. Light comes through many parts of the A/C unit’s mechanism itself (not merely from above and around the frame), and manufacturers do absolutely nothing to incorporate light blockage into their design (and they add a bunch of bright green LED indicators to boot). Covering the air vents would of course defeat the purpose. (I live in Japan now and I use a Japanese-style installable A/C unit, which solves the problem, but these are not applicable to people who live in apartments w/o built in A/C units.) I tried in vain to devise a DIY solution to this; I wonder if anyone has a good idea on how to make a window A/C “dark.”

    1. Cool. I just cover everything with electrical tape, block the windows around it as tightly as possible, and wear a sleep mask.


  7. Hang your curtains from a “return rod” that allows the side of the curtains to wrap around so they meet the wall. This helps a lot when there is light that leaks on the sides. I found inexpensive return rods at W***mart.
    Dark fabrics seem to be more effective than light ones. I have unlined, dark green “velvet” curtains that block light much better than off-white “blackout” panels that I purchased and returned.
    Also a cornice box or pelmet at the top can help light that leaks in at the top of the window.

  8. One traditional method for Alaskan summer is to tape aluminum foil to the glass. It’s ugly but cheap and effective.

  9. I didn’t realize how important a dark room was until our power went out one night and I had the best nights sleep ever. I was amazed. The room was COMPLETELY dark. I have installed blackout blinds as you suggest but I still have light leaks around the edges. Need to work on that. Light finds lots of ways into the room.

  10. Instead of an inside curtain, I mounted “panda film” (a black/white poly film). This is used, among other things, by indoor marijuana growers to simulate artificial changes in the seasons. It blocks 100% of light and has not deteriorated after years in the sun. I have a normal shower curtain rod mounted at the highest possible point inside my window frame, with the film draped over the top of shower rod and lightly taped in place to prevent it from falling off one side of the rod. White plastic faces the outside of the window, and is mostly obscured by the existing white blinds my landlord installed. Black plastic faces inside the room, but is mostly obscured by nicely hung outside blackout curtains I installed (Walmart, very similar to the ones shown above)

    This plastic film comes in 10′ wide rolls at about $1/linear foot, so with the shower rod my all in on materials is less than $20 per window for the inside portion, much less than specialty blackout blinds. It’s also easy to install and remove, a plus for anyone who moves often or doesn’t want to mess with removing and replacing existing fixtures in a rented home. If you want to open your windows like Chris is showing, there are specialty light-proof zippers you can install to open and close the film.

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