Bunk Bed Mattress Size Guide

Last Updated On September 27th, 2023
Bunk Bed Mattress Size Guide

Key Takeaways

  • Bunk Bed Versatility: Bunk beds are a versatile choice, offering various mattress sizes from twin to king, making them suitable for children, teens, adults, and even couples.
  • Mattress Sizing: Common bunk bed mattress sizes include twin, twin XL, full, full XL, queen, and king. The choice depends on factors like the room size, ceiling height, and intended users.
  • Types of Bunk Beds: Bunk beds come in various configurations, including standard, shorty, triple, L-shaped, loft, futon, RV, trundle, and more, catering to different needs and preferences.

Bunk beds are excellent for a child’s bedroom or when you’re looking to save space. Not all bunk beds have the same small twin bed, either, making them a usable option for all sorts of people. While twin mattresses are still common for bunk beds, you can find bunk beds that fit up to king size beds.

Whether you’re looking to maximize space or house as many guests as possible, knowing your sizing options is useful so you find the right bunk bed mattress. Let’s take a look at some of the common bunk bed mattress sizes and dimensions on the market.

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Twin Mattress

Twin bunk bed mattresses are 38 inches wide and 75 inches tall. The typical bunk bed will fit twin mattresses and the same goes for bunk beds with unique frames such as loft, triple, or short bunk beds.

A twin size mattress suits toddlers, children, teens, and shorter adults. One twin mattress is too small to fit more than one person, but since most bunk beds feature two mattresses, this shouldn’t be an issue.

Twin XL Mattress

Twin XL mattresses are 5 inches longer than standard twin mattresses, making them 38 inches wide by 80 inches long. A twin XL bunk bed is common for teens and dorm rooms as they suit sleepers over 6 feet tall. Plus, twin XL bunk beds work well for growing children, so there’s no need to worry about changing their bed frame or mattress out too often.

Full (Double) Mattress

Full mattresses are one of the wider mattresses suited for bunk beds at 54 inches wide and 75 inches tall. A full size bed isn’t quite as long as a twin XL bed, but is wider, so there’s more room for sleepers to spread out at night.

Full size mattresses aren’t quite large enough to fit two teens or adults. If anything, two children can share a full mattress when in a pinch, such as during a vacation or sleepover.

Some bunk beds may feature two full mattresses, but it’s more common to see a full mattress on the bottom bunk with a twin or twin XL mattress on the top bunk. As mattresses get bigger, they weigh more, making them less suitable for the top bunk.

Full XL (Double XL) Mattress

Full XL bunk bed mattresses are 54 inches wide and 80 inches tall, so they’re 5 inches taller than traditional full beds. They’re an excellent option for single sleepers who are taller or need extra room to stretch out at night. Despite being longer than standard full mattresses, they’re still too small for more than one sleeper.

Queen Mattress

Bunk bed queen mattresses are 60 inches wide and 80 inches tall. They’re a good choice for teens, adults, and couples. Queen mattresses are normally just the bottom bunk, while the top bunk will likely either be a twin or twin XL mattress. A queen and twin or twin XL mattress bunk duo works well for families in vacation rentals so everyone can share one room.

King Mattress

King mattresses are the largest bunk bed mattress size, measuring 76 inches wide and 80 inches long. Like full, full XL, and queen mattresses, king mattresses are only ever the bottom bunk on a bunk bed.

Bunk beds with king mattresses are one of the more uncommon types of bunk beds. After all, king mattresses are most popular amongst adults and couples, who likely won’t want to share their bedroom with a third person. Some vacation homes might have king mattress bunk beds, but beyond that, the majority of couples won’t reach for a king mattress bunk bed.

Types of Bunk Beds

Although most bunk bed frames are just one mattress stacked over another, these aren’t the only type of bunk bed frames out there. Other bunk bed frames are built to maximize space, whether it includes storage units or multipurpose furniture.


The standard bunk bed features one bunk over the other and is usually around 70 inches tall. It’s easily the most common bunk bed on the market and is a good option for many homes, such as apartments, dorm rooms, children’s rooms, and vacation homes.

The standard bunk bed size arrangement can feature two twins, twin XLs, or even a twin over a full mattress or bigger.


Shorty bunk bed frames are smaller and shorter than standard bunk beds, generally being around 55 inches tall. They’re a safe option for young children who need or want a bunk bed since the frames aren’t tall, minimizing the risk of injury in case a child falls out of the top bunk.

Since shorty bunk beds are less tall than standard bunk beds, they may not be as comfortable for teens or adults. The bottom bunk has less overhead clearance than standard bunks, making it uncomfortable to sit upright in bed if you’re not a child.


A triple bunk bed is similar to a standard or shorty bunk bed, only it features three beds stacked over the other, not two. They’re common in vacation homes or rentals because they fit as many people as possible.

Since triple loft bunks feature three beds, they can be over 90 inches tall. It’s important to have tall ceilings so sleepers have enough overhead clearance.

Like standard bunk beds, the bottom beds of triple bunks may be full, queen, or even king sizes to fit extra sleepers, though this isn’t common.


L-shaped bunk beds feature two top bunks connected at the corners in an L-shape. This way, there’s open space beneath the bunks for toys, a desk, or whatever else, but two people can still easily share a room.

Some children may see the top bunk as more appealing than the bottom bunk. So, for kids sharing a bedroom, an L-shaped bunk bed might also stop the potential argument of who gets the top bunk.


Loft bunk beds only have a top bunk and have open space where the bottom bunk would have been. A loft bed is a good option when trying to maximize a small space for a single person. Rather than a bottom bunk, a person may put a couch, desk, dresser, or use it as a play area for a child, making a small bedroom feel bigger with freed-up room space.


Futon bunk beds are another type of frame that only feature a top bunk, but in the place of the bottom bunk is a futon. Futons are couch-bed duos, so during the day, you have the space to sit, relax, and perhaps some TV. And at night—or if you have guests—simply unfold the futon and it functions as a bed.


RV bunk bed mattresses are the ones you find inside RVs, motor homes, and campers. Some semi-trucks also feature RV bunk beds. They’re not much different than the standard bunk bed. The frames are simply built into these vehicles instead of being standalone objects.


A trundle bunk bed looks like any normal bunk bed, only it features an additional pull-out mattress from under the bottom bunk. A trundle bed is generally thin and small, making it a good option for the occasional guest.

The third bed will either fit into a large drawer under the bottom mattress and sit close to the ground, or on a pop-up frame so guests are higher off of the floor. Drawer-style trundle bunk beds can double as storage space if you remove the third mattress.

More Mattress and Bedding Size Guides


Is a bunk bed a good idea?

Bunk beds are a fun, space-saving bed frame if you live in a small home or apartment or have a small bedroom. After all, you can fit two, even three people in the space of one as long as your ceilings are tall enough. Some bunk beds come with storage options as well so you can maximize your space.

A bunk bed is a good choice for a guest room, a kid’s room, vacation homes, and cabins. While many of us only associate bunk beds with children’s rooms or dorms, they come in all shapes in sizes to fit single adults and couples as well.

How much room do you need for bunk beds?

Bunk bed frames aren’t much larger than regular bed frames, at least when it comes to the square footage of your bedroom floor. Instead, consider your ceiling height when deciding whether or not you have the space to fit a bunk bed.

There should be between 30 to 36 inches of clearance between the top of the mattress on the top bunk and the ceiling. This means your ceilings should be 100 inches high, or 8 feet and 4 inches high.

How thick should a bunk bed mattress be?

The top bunks of bunk beds have low-profile mattresses and should be no taller than 6 inches thick. Bunk bed safety guidelines explain how the top of the mattress on the top bunk should be at least 5 inches shorter than the bunk’s guard rails. Unless you have extra-tall guardrails, too thick of a top bunk mattress poses a safety threat.

There’s no specific mattress thickness guideline for the bottom bunk. Still, it’s worth considering the sleeper’s overhead clearance between the top of their mattress and the top bunk so they can sleep upright. Bottom bunk mattresses should generally be between 8 to 10 inches thick.

Avoid using thick box springs as a mattress foundation for your bunk bed’s foundation. Instead, stick to bunkie boards, plywood slabs specifically designed for supporting bunk bed mattresses.

If your mattress needs a more supportive bed foundation than what a relatively thin board can provide, it’s not the right choice for a bunk bed frame.

Can you use a bunk bed mattress on a regular bed?

It’s fine to use bunk bed mattresses on regular bed frames so long as the bunk bed mattress and the bed frame are the same sizes. So, if you have a twin bunk bed mattress and a twin bed frame or something similar, that works fine. Since bunk bed mattresses come in standard mattress sizes, it is easy to transfer them to another bed frame.

Something to remember when putting your bunk bed mattress onto a regular bed is bunk bed mattresses are generally thinner than the average bed to maximize overhead clearance and avoid exceeding the bunk’s weight capacity. Regular mattresses are thicker for comfort’s sake, so it may be worth looking into a regular mattress.

Does a bunk bed need a special mattress?

No, so long as your bunk bed mattresses are the right thickness, you can use whatever type of mattress you prefer!

Some popular types of mattresses for bunk beds include innerspring mattresses, hybrid mattresses, latex mattresses, and memory foam mattresses. Foam mattresses provide more cushioning for the hips and shoulders to relieve pressure points, while coil mattresses offer more breathability.


When it comes to bunk bed mattresses and appropriate bed frames, you have a wide variety of options. The same goes with the bunk bed frames—there are all sorts of frames to suit different needs and spaces. When weighing your mattress size options, consider who the bed is for, how often it’ll be used, and how long you want it to last.

About the author

Mitchell Tollsen is a graduate student and a freelance writer who’s contributed to the Early Bird blog for three years. Mitchell’s always been fascinated by the science of sleep and the restorative processes our bodies undergo when at rest. The self-titled “Sleep Expert” is always looking for ways to improve his shut-eye, and throughout the years has implemented numerous lifestyle changes and tried dozens of sleep-promoting gadgets to determine the best ways to truly get better rest.

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