You likely already know that twin and full sized mattresses are smaller than the more commonly purchased queen-sized mattress, but the two smaller options have different widths and can serve different purposes. Twin and full mattresses may work well for children and teens, single sleepers, guest rooms and small spaces. The main difference between twin and full-sized beds is their width. 

Knowing the difference is essential to help you plan for a room and ensure you’ll be comfortable sleeping in the bed you choose. 

Twin vs. Full Size Bed Chart

The name “twin” can be deceiving, especially because twin-sized mattresses are also known as single mattresses. They are the most narrow standard bed, but they do come in extra long (xl). A standard full bed, also known as a double,  measures more than a foot wider than the standard twin bed, and it also comes in xl. You can find the specific dimensions in the twin vs. full chart below. 

Twin Twin XL Full Full XL
Width 38”38”53”53”
NicknamesSingle Long singleDouble Long double
Best forOneOne or
One tall
One or
One tall or
Two tall

Full Mattress vs. Full XL Mattress

Standard full beds measure 75” long, meaning that they have ample length for most sleepers of average height. Full xl beds, or long doubles, can accommodate those 6’ + people who don’t like to have their feet hang off the end of the bed. 

If you are buying for a child who seems likely to grow tall, you may be able to save some money by purchasing a full xl mattress that will continue to accommodate them without having to buy a larger mattress later on. Because you can readily find bedding to fit either the full or the full xl, the only real considerations for choosing between these mattress sizes is the height of the sleeper and the size of the bedroom.

Full Size Bed Considerations

At 53” wide, full beds will comfortably accommodate most single sleepers. They are also a good purchase for a guest room because they take up less space than a queen but offer more wiggle-room than a twin. These beds can fit couples who are comfortable sleeping close together, but a queen mattress is usually the most popular choice for two sleepers. 

If you have limited space and you are trying to determine whether to get a full vs. twin, you may want to think about the smaller mattress. 

Twin Mattress vs. Twin XL Mattress

While standard twin beds are best suited to children, twin xl beds can accommodate tall teens and adults. The twin xl provides an extra 5” of length, which offers enough length for people above 6ft. 

The standard twin mattress is most often used in bunk bed sets and especially small bedrooms, as it is the smallest standard size mattress that you can buy. The twin xl is the most popular choice for teens and college dorms because it still offers space-saving on the width but has enough length for tall people. You may also want to buy a twin xl for a small guest room.

Twin Size Bed Considerations

Because twin beds are 38” wide, they will fit just about anywhere. They work well for children and as transitions between toddler and larger beds. They also have the least expensive bedding and accessories. 

If you get a twin xl, you are more likely to be able to accommodate a wider range of sleepers, but adults and large teens may not be as comfortable in a twin vs. full bed. The narrow width may also be uncomfortable for combination or active sleepers. 

Choosing The Right Bed Size

When choosing whether to purchase a full vs. twin size mattress, you will likely want to consider the size of the room, the number of sleepers and the cost of bedding accessories. 

Room Size

When buying a new mattress, keep the size of the room in mind. If you are considering a full mattress, your room will need to be at least 10’ by 10’ to allow for comfortable movement around the bed. 

If your room is smaller, consider going down to a twin to avoid feeling squished as you move about the bedroom.

Single Or Co-Sleeping

If you sleep alone, you will likely be comfortable in a twin or full-size mattress, but if you cosleep with a partner, a twin will likely be uncomfortable. Even a full may feel cramped for some couples, so it is especially important to have good edge support in your mattress to avoid feeling like you are falling off the side. 

If a full feels too cramped for you and your partner, consider opting for a queen to ensure that you have enough room. 


Smaller mattresses have lower prices, so it’s important to consider your budget before you begin shopping.  If you are low-budget shopping for a child or a guest bed, you may be fine with a twin or twin xl. If you are a cost-conscious couple, you may be able to save money by buying a full instead of a queen. 

Especially in terms of accessories, you can get better value for a full than what you would get for a queen and again better value for a twin than you would for a full.

Bedding Accessories

Finding bedding accessories for twin or full beds is easy — these standard sizes are stocked just about anywhere you want to purchase home supplies. However, the larger the mattress, the more expensive the bedding. 

If you are especially budget conscious, you will be able to save more money on twin sized accessories compared to that of full sized beds. 

Slumber Yard’s Final Thoughts

Buying a twin or full mattress could help you save on money and bedroom space. However, you’ll need to consider your specific needs and your budget when deciding between the two mattresses. You can certainly save money by purchasing a twin mattress, but your child may outgrow it, or your adult guests may not be very comfortable staying the night. 

If you have enough bedroom space for a full mattress and think you’d like the additional width, you will pay more for the mattress as well as the accessories. Luckily there are lots of options to save money on either of these bed sizes and even have them delivered to your door with options like Casper and Purple


What is the best mattress size for a toddler or young child?

A twin bed is best for a toddler or young child, but you may want to consider a twin XL if you think that your child may grow to be quite tall, and you would rather not buy a replacement mattress in a few years.

Which mattress should I buy for my tall teen?

Tall teens will likely be comfortable in a twin XL or a full XL since both measure at 80” in length. However, they will have more wiggle-room in the additional width provided in the full XL.

How much wider is a full mattress than a twin mattress?

A full mattress is 15” wider than a twin mattress.

What are the dimensions in centimeters?

Twin – 96.5 by 190.5

Twin XL – 96.5 by 203.5

Full – 134.5 by 190.5

Full XL – 134.5 by 203.5