Fitted vs. Flat Bed Sheet: What is the Difference?

July 30, 2021 | Casper Editorial Team

You spend an average of eight hours a night snuggled up to them so, if you haven’t already, it’s time for you to get properly acquainted with your bed sheets

So, let’s start by answering one of the most common questions around bed sheets: what is the difference between a fitted bed sheet and a flat bed sheet? 

A flat sheet (used on top) is a rectangular sheet, whereas a fitted sheet (used on bottom) has its corners, and sometimes sides, fitted with elastic.

Read on to learn more about the purpose of a flat sheet vs fitted sheet and the advantages of each. 

Missing a flat or fitted sheet in your bedding? Casper’s premium bed sheet sets will have you covered with both, literally. Find all you need with a set of sheets tailored to your preference.

What is a Fitted Sheet Used For?

You might be wondering, “What is a fitted sheet?” Known also as a bottom sheet, a fitted bed sheet can be easily recognized by its four elastic corners used to hug the perimeter of your mattress. Whether you prefer tencel vs cotton material, a fitted sheet serves as a protective barrier for your mattress, and its soft even surface provides you with an added layer of comfort as you sleep each night. 

Using fitted sheets on your bed boasts a number of advantages. Here are a few to consider:

  • Easy to clean – Washing your fitted sheet doesn’t require a trip to the dry cleaners—all you have to do is toss it in the wash with your flat sheet (we’ll get to that) and pillow cases.
  • Can extend the life of your mattress – While most mattresses have a lifespan of 7-10 years1, you can do your part to increase your mattress’s longevity by protecting it from dust build-up with a fitted sheet.
  • Soft surface for improved comfort while sleeping – Your mattress might be as soft and comfortable as a supportive cloud (especially if you’re sleeping on Casper’s Nova Hybrid). However, a soft, supple fitted sheet can elevate your comfort so you’re not just sleeping on a cloud, you’re sleeping on cloud nine

What is a Flat Sheet Used For?

Flat sheets, as the name suggests, lay flat on top of your bed. Also known as a top sheet, they can be tucked under the bottom corners of your mattress but may not stay as securely in place because they lack the elasticity of a deep fitted sheet. 

Though many people agree that a fitted sheet is a standard bedding essential, there is a bit more controversy surrounding the use of flat sheets. Many older Americans believe that bedding sets are not complete without top sheets, while some younger members of the millennial generation believe them to be extraneous.

Here are some of the arguments that support the use of a top sheet:

  • For cleanliness to prevent dirtying your duvet
  • For a cooler night’s sleep in warm weather months
  • For hygiene reasons, they can be easier to wash with more regularity than your duvet 

Can You Use a Flat Sheet as a Fitted Sheet?

If you don’t have a fitted sheet in your linen closet, a flat sheet can be a viable alternative to protecting your mattress and ensuring a good night’s sleep. Though, the corner-hugging features of a fitted sheet are helpful if you’re wondering how to keep sheets on your bed. However, a flat sheet is still an option to consider if you’re in a pinch. 

Avoid getting tied up in knots overnight by following these steps to turn your flat sheet into a snug-fitting bottom sheet:

  1. Start by using a flat sheet that is big enough for the job. You’ll want to use something that is large enough to drape over all four corners of your mattress and will provide excess material on all sides to be tucked underneath. 
  1. Next, lay the sheet flat on your mattress, making sure it is well-centered and smoothed out to prevent bunching. 
  1. Since this will be used in place of a fitted sheet, you’ll want to take special care to ensure all four corners are folded securely underneath the mattress to prevent it from coming loose overnight. The best method for this is to make square corners, a tightly-tucked folding method commonly seen on hotel or hospital beds. 

Here’s how to get crisp corners that won’t come untucked while you sleep:

  1. Starting at the base of the bed, lift up the mattress and slide the overhanging fabric of the flat sheet under the mattress across the entire foot of the bed. 
  1. Take the extra untucked fabric from either side and fold it up and crease it to form a triangular shape over the top side of the mattress. Tuck the lower drape of this edge under the mattress, and bring the remaining fabric straight down. Complete the corners by folding this piece tightly under the mattress. 
  1. Repeat these steps at the head of the bed, creating four crisp corners and a flat sheet that lays snugly atop your mattress. 

Are Fitted Bed Sheets Better?

Are fitted bed sheets better than flat sheets? That answer really depends on you!

The flat sheet vs. fitted sheet debate will likely continue to be a hot topic of discussion as time goes on. Some sleepers will remain faithful to the flat sheet, while others will find no need for it as long as they’ve got a duvet or a blanket for comfort. And, as you’ve just seen, a fitted sheet may not be a necessity if you’ve learned to master the flat sheet swap. 

As with other things such as footwear and clothing, bedding is another personal possession that often comes down to individual preferences. What’s a comfortable sleeping habit for you might be bothersome for someone else, and vice versa. 

To that end, fitted sheets tend to offer a more slip-resistant option for protecting your mattress than flat sheets. If you choose to skip flat sheets altogether, you’ll want to keep your duvet clean by purchasing a duvet cover. 

How Do You Know Which Sheet Is Best For You?

If you’re unsure about deciding whether a flat sheet or a fitted sheet is right for you, don’t worry. You can easily figure out whether going with or without these sheet types leads you to the best possible sleep. 

Here’s how:

  • Borrow an extra flat sheet and give it a try – Go a whole week using a flat sheet to cover your mattress. Wash and make your bed to see if you don’t mind the extra folding and tucking to ensure mattress coverage.
  • Go without a flat sheet, but try a fitted sheet  Snuggle up with just your duvet cover, pillow, and fitted sheet. Give this sleep arrangement at least a few days to see if it makes a difference in your sleep quality.
  • Try them both – Use a flat sheet to cover you while the fitted sheet hugs your mattress. If you wake up and find you’ve kicked your flat sheet off the bed, you might not need a flat sheet. But if you wake up snug as a bug in a flat sheet, you may have found your perfect bedding combo. Don’t forget to wash and dry your bedding and remake your bed. If the flat sheet tucking method is easier on you, you might do well to stick with that method, as opposed to a fitted sheet with elasticized corners. 

Whatever you decide, there is no right answer to the fitted vs. flat sheet debate. There’s only what’s right for you and your sleep.

Changing and Caring for Your Sheets

Fitted and flat sheets each have their own unique uses and sets of advantages, but both should be treated with the same amount of care. Since sweat, bacteria, and skin cells can build up on your sheets over time, it’s important to stick to a regular cleaning schedule to avoid having the same kind of grime seep into the fibers of your mattress, too. 

According to Healthline, sleeping on dirty sheets can even trigger things like eczema or contact dermatitis. Additionally, if you’re one of 24 million Americans who suffer from allergies, soiled sheets can cause symptoms such as sneezing and congestion to become worse.2

Here are key preventative measures you should be taking to help them withstand the test of time. A few tips to consider when caring for your sheets:

  • Thoroughly remove makeup before getting into bed to avoid transferring it to your pillow sham and sheets.
  • Consider showering at night instead of in the morning to prevent dirt, sweat, and bacteria accumulated throughout the day from entering your bed. 
  • Discourage pets from getting on the bed. 
  • If tolerated, washing your sheets with hot water will aid in getting rid of unwanted germs. Be sure to check with your bedding manufacturer for specific washing instructions. 
  • Properly bandage any open cuts or wounds to prevent pus or fluid from coming in contact with sheets, pillows, and blankets. 
  • Avoid eating and drinking in bed. 

Take good care of your sheets, and they’ll repay the favor by maximizing the quality of your sleep cycle. 

Shop Fitted and Flat Sheets at Casper

Fitted sheets, flat sheets, or both? Now that you’re equipped with the knowledge to distinguish between the two, you can be a better judge of what’s right for you. Opt for a full set of breathable Hyperlite cooling sheets if you know you’re a sweaty sleeper. Or snuggle up to an ultra-soft set of Sateen Sheets made of 100 percent organic cotton from Portugal.

Whatever your sheet and sleeping preferences, Casper cares about keeping you cozy so that you can catch the highest quality Zs. 


  1. Sleep Foundation. How Long Should A Mattress Last?.
  2. Healthline. How Often Should You Change Your Sheets?.
  3. Today. Do you use a flat sheet? The pros and cons of this controversial bed linen.