Bunk Bed Mattress Sizes and Dimensions Guide with Variations


Bunk beds are beds that are stacked on top of each other. The beds are made so that more people can sleep in less space. This bed setup is often found in kids’ rooms and college dorms.

The top bunk of a bunk bed shouldn’t be any thicker than 6 inches. A mattress that is thicker than that makes the guardrail too high and makes it more likely that you will roll out of bed.

Bottom bunks should be 8 to 12 inches thick, and children’s mattresses should be firmer, so they don’t sink or suffocate while sleeping.

In this article, we’ll talk about the different bunk bed mattress sizes. Also, determine if a bunk bed is right for you based on your needs, space, and budget.

Bunk Bed Mattress Sizes and Dimensions

Before you buy and set up your bunk beds, you should measure the space in your bedroom. Ensure at least two feet of clearance on all sides of the bed to help with movement when getting in and out. Below, we describe the standard sizes of mattresses.

Twin Bunk Bed Mattress

Small toddlers and adults who want to sleep alone can consider twin-size mattresses. A twin-size bed has a width of 38 inches and a length of 75 inches. The minimum recommended room size is 7 by 10 to accommodate a twin bed.

Twin XL Bunk Bed Mattress

Adults or teenagers over six feet tall will benefit from the extra length of a twin XL mattress. The width is 38 inches, and the length is 80 inches. You’ll need a space that’s 9 ft. 6 in. broad and 10 ft. 6 in. long to accommodate your twin XL bunk bed.

Full Bunk Bed Mattress

One adult alone or two young children do well in full beds. It measures 54 inches in length and 75 inches in width for a full-size bunk. For maximum comfort, a bed measuring a full size should be used in a space measuring 9’6″ by 10’6″.

Full XL Bunk Bed Mattress

Teenagers and taller adults can both sleep comfortably on full XL mattresses. It measures 54 inches in width and 80 feet in length, making it a queen-sized bed. You need a space of at least 9’6″ × 10’6″ to accommodate a full XL bed.

Queen Bunk Bed Mattress

Two adults can sleep comfortably in a queen bed. The dimensions of a queen-sized bunk bed mattress are 60 inches in length and 80 inches in width. This bunk bed should be put in a 10 by 10-foot room.

King Bunk Bed Mattress

Taller or larger-framed couples will benefit greatly from king bunk beds. Two adults and one child can sleep on these bigger mattresses, or three kids can sleep.

The standard dimensions for a king bed are 76″ in length and 80″ in width. A 12×12 foot space is perfect for a king-sized bunk bed.

Bunk Bed Mattress Sizes Chart

The following chart provides a breakdown of the available mattress sizes for bunk beds:

Mattress SizesDimensions in InchesDimensions in Centimeters
Twin38 inches X 75 inches             96.5 X 188.0 cm
Twin XL38 inches X 80 inches             96.5 X 203.5 cm
Full54 inches X 75 inches             134.5 X 190.5 cm
Full XL54 inches X 80 inches             137 X 203.5 cm
Queen60 inches X 80 inches             152 X 203.5 cm
King76 inches X 80 inches             193 X 203.5 cm

Consider Mattress Thickness

The thickness of the mattress should be considered when buying one for a bunk bed to ensure the top bunk is secure.

The guard rails on top bunks keep people from falling and getting hurt during the night. So, if the mattress on your top bunk is excessively thick, it can wind up being higher than the safety rails, putting the occupant at risk of falling and hurting themselves.

It’s important to note that the head’s distance from the ceiling decreases with the thickness of the mattress on the top bunk.

The best mattress for the top bunk is 4 to 6 inches thick. Thinner mattresses fit within the guard rails and are easier to get in and out of, make, and launder.

There aren’t many safety precautions for bottom bunk beds, and there aren’t many worries either—regular mattresses and bed frameworks also apply to bottom bunks. You can pick any thickness of mattress for the bottom bunk.

Benefits and Drawbacks of Bunk Bed Mattresses


Bunk beds are great for people who want to save money while shopping. Only a one-bed frame will be needed. You won’t need a foundation or box spring to match your mattress.

Bunk beds are also good because they save space. The guest room can accommodate two or more persons. You won’t need a cot, futon, rollaway bed, or air mattress when you have overnight guests. This setup also lets you store things under the bed.

Bunk beds come in different sizes, so you can use them even as your kids get bigger. They can also be used to sleep with adults. Bunk beds can also be used as places to store things. Built-in storage spaces are available in several beds and bed frames.


One big problem with bunk beds is that they don’t keep out noise or motion very well. People who don’t sleep well may want to avoid bunk beds. Those on the bottom bunk may hear those on the top bunk tossing and turning in bed.

Bunk Bed Variations

Aside from the different sizes of mattresses, bunk beds also come in different sizes. These various forms and shapes can fit various requirements and living areas.


The traditional bunk bed, which stacks two beds, is the most frequent layout for this type of bed. While twin over twin, full over full, and queen over queen are the most common mattress configurations for bunk beds, conventional bunk beds can accommodate any of these sizes.


A triple bunk bed consists of three bunks stacked on one another. Most of the time, they only fit twin beds, which are between 75 and 82 inches tall, so you need a high ceiling to use them.

Triple Loft

In a triple loft bunk bed, the two upper bunks are joined at a right angle, and the third bunk is tucked in directly beneath one of the upper bunks.

There is enough workstation or a couch in the open area under the second top bunk. The triangular design of triple loft bunk beds makes them ideal for placement in a corner.


Shorty bunk beds, which stand between 50 and 55 inches tall, are a low-profile variant of a normal bunk bed.

A short bunk bed lessens but does not eliminate the danger of damage if someone falls off the top bunk. It’s a great solution if you need a bunk bed but have low ceilings.


Bunk beds with trundle beds are similar to regular bunk beds, but the bottom bed has a mattress that slides out from under it. When you need to sleep three people but only have a small amount of space, trundle beds can help.


The two bunks in an L-shaped bunk bed are perpendicular to one another rather than precisely stacked. Unlike the top bunk, which is horizontal, the bottom bed is vertical. L-shaped bunk beds usually have more space for storage than regular bunk beds, but they take up more room because of their shape.


A futon is placed in the place of the bottom bunk on bunk beds with a futon as the top bunk. During the day, a futon can be used as a couch. At night, it can be made into a mattress.

Most of the time, futon mattresses are thinner than regular mattresses, and they usually come in full size.

This couch-bed set is suitable for compact apartments or dorm rooms when you need to make the most of your available living space.


How many children can sleep in a bunk bed?

Depending on the size of the mattress and the type of frame, a bunk bed can sleep anywhere from two to three kids. Queen and king-sized mattresses can each sleep two to three children.

Those who wish to accommodate more than two children can go for a triple loft, L-shaped bunk bed, or trundle bunk bed. Also important is the size of the children.

Will a bunk bed split you up?

Some bunk beds can be taken apart to make two separate loft beds. This lets you keep some space under the bed for storage without raising the bed as high off the ground.

If you have children who may eventually want their rooms, buying bunk beds with separate beds is a good choice.

What is the ideal thickness for a bunk bed mattress?

The best bunk bed mattress is about 8 inches thick. The comfort layer should be at least 2 to 3 inches thick. And the base should be about 6 inches thick for the most comfort. But make sure it’s not too thick because that could cause you to fall and hurt yourself.

How high do most bunk beds stand?

Around 63 inches measure the height of a typical bunk bed from the ground to the top bunk.

Can grown-ups sleep well in a bunk bed?

Whether or not an adult can sleep comfortably on a bunk bed depends on the size. A set of full or queen-sized bunk beds is ideal for adults.

Are stairs on bunk beds safer?

Most bunk beds are equipped with a tiny ladder to make it simple to access and exit the top bunk. More and more bunk beds have stairs instead of a ladder.

Especially for small children, bunk beds with steps and handrails make climbing to the top bunk simpler and safer.

Compared to bunk beds with ladders, bunk beds with steps take up more room and are typically more expensive. But sometimes, the stairs can be used as storage drawers, which can make up for the extra cost and space they take up.


Many mattresses and suitable bed frames are available for use with bunk beds. Likewise, many bunks’ bed frames accommodate various needs and available places.

When deciding on a mattress size, it’s important to think about the intended sleepers, the bed’s intended uses, and the desired lifespan of the mattresses.

Bunk beds are a cheap and easy way for more than one person to sleep. Both kids and adults can use bunk beds. There are different bunk bed mattress sizes and shapes.

How you choose a mattress depends on your needs and how much money you have. The frames for bunk beds can be standard, lofted, L-shaped, or have a trundle. When choosing a bunk bed frame, think about the size and height of your bedroom.

About the author

Best Mattress Advisor Editorial Team

Our dedicated team of experts, with more than two years of experience in the bedding industry, is committed to helping you achieve your best sleep yet. From in-depth reviews to comprehensive guides, we cover almost every aspect of sleep products, including mattresses, pillows, bed frames, and accessories. Explore our website and discover why we're the go-to resource for all things sleep-related.

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Best Mattress Advisor Editorial Team

Our dedicated team of experts, with more than two years of experience in the bedding industry, is committed to helping you achieve your best sleep yet. From in-depth reviews to comprehensive guides, we cover almost every aspect of sleep products, including mattresses, pillows, bed frames, and accessories. Explore our website and discover why we're the go-to resource for all things sleep-related.

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