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Limited Time: Up to 25% off sitewide

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.

Twin and Twin XL Mattress Size Comparison

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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

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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Pairing Your Mattress With An Adjustable Base

MotionInABox™ 1.0

The MotionInABox™ 1.0 adjustable base bed is a great way to fully customize and enhance your sleep experience. The MotionInABox™ 1.0 is available in many sizes. This adjustable base can accommodate a twin XL mattress, but not a twin mattress. If you are interested in this bed and are deciding between a twin or a twin XL mattress, the twin XL may be the way to go.

MotionInABox™ 2.0

The MotionInABox™ 2.0 is an even more customizable adjustable base bed, that gives you full body adjustability as well as under bed lighting, massage settings, and USB ports built into the bed. Similar to the MotionInABox™ 1.0 adjustable base, the MotionInABox™ 2.0 is available in the twin XL size, but not the twin size. This may be the sign you need to opt for the twin XL over the twin.

Read Our Adjustable Base Buying Guide

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!

Original Product Image
11” multilayer foam construction designed with CoolRest® Gel memory foam to bring you cool, comfortable memory foam support.
Starting at $591.75 $789
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Azul® Product Image
11” medium-soft multilayer foam construction with an UltraCool® soft knit cover and our most advanced cooling system to keep you sleeping comfortably.
Starting at $704.25 $939
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Tranquillium® Product Image
12” and three layers of memory foam support infused with CoolRest® technology for those seeking maximum support and comfort.
Starting at $786.75 $1,049
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