image of child on twin XL mattress

Twin XL Size Bed Dimensions Guide

If you’ve ever gotten into a twin bed and felt your feet dangling over the end, you’ll be pleased to know that there’s a version of the twin that just might work for you (or your growing adolescent). It’s called a twin XL mattress, and it’s commonly the size you’ll find in college dorm rooms.

“I’m a big fan, as I always had one growing up,” says Prudence Bailey, founder and principal designer of Prudence Home + Design in Connecticut. “A twin XL is very universal and can fit any bedroom.”

Beyond being a good option for college students and taller adults who sleep by themselves, you can even put two twin XL mattresses together to create what’s known as a split king. This is a popular mattress choice for couples who have different sleep preferences.

Here’s how to determine if a twin XL mattress is right for you, from twin XL dimensions to design considerations to keep in mind.

Twin XL dimensions

A twin XL mattress measures 38 inches wide by 80 inches long.

Difference between twin and twin XL

A twin mattress is 38 inches wide by 75 inches long. A twin XL is 5 inches longer than a standard twin.

Split king vs. twin XL

A split king is comprised of two twin XL mattresses placed side by side. In total, a split king mattress measures 76 inches wide by 80 inches long—the same dimensions as standard king.

twin xl dimensions mattress size infographic

Benefits of a twin XL

A twin XL mattress has quite a few things going for it. Here are the biggest benefits:

  • Twin XL beds are great for teens. Since teens often experience growth spurts, the added length of the mattress will be helpful. Measuring 80 inches long (roughly 6 feet 7 inches), this is a particularly good option if you believe your teen will be over 6 feet tall. If you’re a taller adult who has a small bedroom, you may also benefit from choosing a twin XL mattress.
  • Twin XL dimensions make for a nice fit in dorm rooms. “Twin XLs are ideal for college students because they provide more length, which is great for kids who study in bed or want to hang out with friends on their bed,” notes Bailey.
  • If you and your partner have different sleep needs, you can put two twin XL mattresses together to make a split king. For example, if you like a firm mattress but your partner prefers a soft mattress, consider a split king so each of you has a separate sleep surface with your preferred mattress firmness.

Our Best Twin XL Mattress for Children

Saatva Youth

This dual-sided innerspring mattress provides optimal support and comfort to children of all ages. Simply flip it over from the 3+ side to the 8+ side when your child is ready.


Drawbacks of a twin XL

The twin XL mattress isn’t without its downsides. Consider these points before you buy one:

  • It’s too small for two. Given that a twin XL mattress is only 38 inches in width total, it doesn’t afford much space for two people. A queen size bed, which measures 60 x 80 inches, is the ideal mattress size for couples because each sleeper gets about 30 inches of space to themselves.
  • It can be a challenge to find bedding that fits since a twin XL mattress is less common than a standard twin. That said, twin XL sheet sets do exist. Don’t try to fit full size sheets onto a twin XL bed. While full size and twin XL mattresses are both 80 inches long, a full size mattress is 16 inches wider than a twin XL, meaning full size sheets won’t fit properly. (Here’s what you need to know about special mattress sizes before you buy one.)
  • You’ll pay more for a twin XL than you would a standard twin. “Twin XL beds are a bit more expensive than regular twins,” says Bailey. Plus, not all mattress retailers stock twin XLs regularly, she adds.
child sleeping in twin xl mattress

Considering a twin XL mattress? Make sure your child’s bedroom can accommodate the added length.

Design considerations for a twin XL bed

Every mattress comes with its own set of design considerations, and twin XL beds are no different.

If your child is considering a twin XL mattress for their dorm room, “make sure the room can accommodate the extra length first,” advises Bailey. “Since dorm rooms are small, consider elevating the bed bunk style so a desk can be put underneath. Being smart about space is key in a dorm room.” At minimum, a bedroom should be 7 feet by 10 feet to accommodate a twin XL mattress.

Outside of the dorm room scenario, Bailey says twin XL beds are a good choice in a long and narrow room along the side of a wall. After confirming the bedroom can support the additional length of a twin XL mattress size, you can think through the décor.

“There are no special concerns when it comes to lighting and other bedroom necessities with a twin XL,” Bailey says. As with any other mattress, you should consider “pretty overhead lighting” and “a place for a lamp and to set down a water glass.” You could also create a daybed with a twin XL and add sconces on either side for reading, as well as a cute table in front for a nightstand, suggests Bailey.

Looking for a Twin XL Mattress? Shop These Options from Saatva

Saatva Classic

Our flagship luxury mattress is expertly engineered with coil-on-coil construction for durability, a layer of memory foam for enhanced back support, and a cushiony Euro pillow top for extra comfort.


Loom & Leaf Memory Foam

Premium memory foam, handcrafted in the U.S. with eco-friendly materials. Breathable organic cotton, cooling spinal gel, and layers of high-density support foam assure a cool, comfortable night’s sleep.


Zenhaven Latex Mattress

100% Talalay latex responds to every curve for pressure-free support and responsive comfort. Talalay latex is supple, resilient, and durable, for the ultimate in elevated sleep. (It’s naturally hypoallergenic too.)


Twin XL mattress foundation

Lastly, you’ll need to think through the foundation. In general, twin XL mattresses can be paired with several foundation types—just be sure to double-check with the manufacturer to see what your mattress is compatible with.

  • A traditional box spring foundation historically contained actual springs in a wood box, but today, it’s more of a fabric-covered or exposed wood frame that supports the mattress and creates a comfortable height for your bed.
  • A platform bed is a modern option meant to be used without a foundation since the mattress rests directly on the platform. Some platform beds come with built-in storage, a great option for dorm rooms or adults in small apartments.
  • A bunk bed usually features two twin mattresses stacked about 3 feet apart, but some manufacturers also make them in twin XL size. It’s typically used in children’s rooms to maximize space.
  • A day bed is a multipurpose piece of furniture—it’s a couch that doubles as a bed, making it a suitable option for guest rooms or small spaces. While daybeds are usually found in the standard twin size, some manufacturers do make twin XL daybeds. There are many different daybed styles—some are on platform bases without arms or a back (in which case you’d need to add pillows so someone could sit back while resting on it), while others have arms and a back made from wood or metal.
  • An adjustable base allows you to raise and lower your head and feet, making for maximum customization and comfort. An adjustable base is a good option if you’re pairing two twin XLs together to form a split king, as you’ll be able to raise your head and feet separately from your partner.

Our Best Split King and Adjustable Base Combo

Solaire Precision Adjustable Air

50 precise firmness settings on each side of the bed for personal customization. Latex and memory foam layers provide luxurious comfort and support.


Lineal Adjustable Base

With weightless, Zero Gravity support, the Lineal adjustable base allows you to set your ideal position for sleeping—and living—with one touch of the remote.


Is a full size bed a better option for you than a twin XL? Here’s everything you need to know about full size mattresses.