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The Difference Between a Twin and a Twin XL

The Difference Between a Twin and a Twin XL

At 38 inches wide, the twin size mattress is the coziest mattress on the market. Although it is possible to share a twin size bed with someone, the twin mattress size is meant for individual sleeping. It may surprise you to learn that there are actually two twin mattress size variants: the twin size mattress and the twin xl mattress. The primary difference between the two mattress sizes is their length. At 80 inches long, a twin xl mattress is 5 inches longer than the twin mattress size. It may not sound like a big difference, but it is significant enough that the two size variants have different practical uses. Below, we discuss the history of the twin size mattress and today’s practical uses for both variants.

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History of the Twin Size Mattress

Today, it is practically unheard of for happily married partners to sleep in separate twin size beds. Most of us see sleeping in separate beds as a sign of trouble in a relationship. Believe it or not, separate beds and twin size mattresses were actually sought after by most couples in the late 1800s and early 1900s. At the time, twin size mattresses were one of the most popular mattress sizes. Two twin size beds were initially desired in the late 1800s for health reasons, with partners trying to avoid breathing each other’s germs. In the early 1900s, separate beds indicated forward thinking for partners who wanted to balance their partnership with autonomy. By the 1920s, having separate twin beds was considered a “desirable, modern and fashionable choice”. In fact, the revolt of partners against twin size beds did not take place until the 1950s and 1960s. A negative association between couples and twin beds still persists, which means the twin mattress size is most commonly used for children or single adults.

Twin Size Mattress

The regular twin size mattress is 38 inches wide and 75 inches long, making it 5 inches shorter than the twin XL mattress size. Due to its cozy size, the twin mattress is perfect for young kids and often fits easily in a child’s bedroom. The twin mattress is also great for a guest room or for small bedrooms – just enough sleeping space without taking up too much room. If you need a twin size mattress for your children’s bedrooms, a guest room, or a smaller room in your home, check out our mattress selection at BedInABox.com.

At BedInABox®, we offer five different mattresses in a twin size, each mattress designed with different sleep needs in mind. You can also buy a bed frame or adjustable base from BedInABox® to completely outfit your twin size mattress.

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Twin XL Mattress Size

The twin XL mattress size is 38 inches wide and 80 inches long, 5 inches longer than the regular twin mattress size. The twin XL is perfect for taller sleepers who need a high-quality mattress in a small space. It is also the most commonly used mattress in university dorms for college students.

The twin XL mattress has an additional, and helpful, function. When you combine two of them, they form a split king mattress. Remember, a king mattress size is 76 inches wide and 80 inches long. That makes the twin XL mattress size perfect to use as a split king mattress on an adjustable bed frame. When you use two twin XL mattresses versus a single king size mattress on a king size adjustable base, then each sleep partner can have his or her own adjustable settings while technically sleeping in the same bed.

At BedInABox®, we also offers five different mattresses that are all available in the twin XL mattress size. We offer a mattress design suitable for everyone, as well as bed frames and adjustable bases perfectly suited for your twin xl mattress. Best of all, if you buy an Azul™  or Tranquillium™  mattress in twin XL and a MotionInABox™  adjustable base at the same time, you qualify for our custom comfort bundle for a savings of 30 percent!

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Both Excellent Options

The twin size mattress and the twin xl mattress are both excellent options for children and taller sleepers. At 38 inches wide, the width of this mattress is perfect for children’s bedrooms, guest rooms, and smaller sleeping spaces. BedInABox® is also happy to offer twin and twin XL mattress sizes to sleep partners, whether you sleep in separate beds or share a split king adjustable bed. Whatever your sleeping needs, BedInABox® has a mattress for you! If you are buying a new mattress, don’t forget to check out our custom comfort bundle!

Frequently Asked Questions


What is a twin XL bed?

The twin XL mattress size measures 38” wide by 80” long and is most commonly used in university dorm rooms for college students. The 5” of extra length the twin XL offers compared to the twin size provides the perfect amount of length for growing kids or single, taller sleepers. All six BedInABox® mattress models are available in the twin XL size.

What is the difference between a twin XL and a twin?

While the twin XL mattress has the same width a twin size mattress (38 inches), the twin XL size features a length of 80 inches, which is 5 inches longer than that of the twin mattress. The twin size mattress and the twin XL mattress are both suited for smaller sleeping spaces such as children's rooms or guest rooms.

Is a twin XL the same size as a full?

No, the twin XL and full size mattresses are two different sizes. A full mattress, also frequently referred to as a “double bed” or a twin full, measures 53 inches wide by 75 inches long while the twin XL measures 38 inches wide by 80 inches long. The twin XL may be narrower, but still provides 5 additional inches of length than the full. BedInABox® offers five of our mattress in a box options in the full size.

Is a twin XL for 2 people?

Two small children may fit on a twin xl bed, but two grown adults likely would not. A twin XL mattress is best suited to single sleepers, and definitely not our first suggestion for long-term sharing. The twin XL shares the same width as a standard twin size mattress, which is another mattress size best suited for single sleepers.