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Mattress Reviews » Bed Size Dimensions

Bed Size Dimensions

There are plenty of things that you need to give careful thought to when you’re considering a new mattress. However, one of the things that you don’t want to spend too much time worrying about is what size mattress you need. That’s why we’ve put together this helpful guide so you know what you’re getting when you’re considering different bed sizes. We’ll cover the dimensions of the various sizes that mattresses come in, and give you some advice regarding what kind of mattress size is best for you given your circumstances and needs.

The bed dimensions are listed in order from smallest to largest, so if you know you need a bigger bed feel free to skip down.  Read on to learn all you need to know about bed size dimensions.

Twin Bed Dimensions

A Twin mattress is one of the most common mattress types. It is the preferred mattress for children and sometimes for guest rooms. A Twin bed is designed to sleep one person only, so it’s not a good idea for couples.

A Twin bed measures 38” by 75” (W x L). As a result, it’s the smallest of the adult mattresses on the market. This mattress size is best for a child who has outgrown the cribs and training beds that re used for toddlers and younger children. A Twin bed is also an acceptable option for a single adult. Twin beds are commonly the size of mattress you get in pieces of furniture like daybeds, bunk beds, and similar bed-inclusive items.

Most of the more popular mattress companies offer their products in a Twin size. As a result, you can usually get the benefits of a high-quality mattress, even if you’re sort on cash or space. It’s also a good option for people who have particular needs from a mattress and don’t have the cash on hand to buy a larger version of the mattress that has the properties they require.

Twin XL Bed Dimensions

A Twin XL is the second smallest mattress option for adults that is commonly available. Nearly all of the most popular mattresses come in a Twin XL form, so you can be reasonably confident about your ability to get the mattress you want in this size.

A Twin XL is the same width as a Twin bed, (38”), but it is 5” longer, bringing the full dimensions to 38” x 80”. It’s best for those that don’t have the budget or space for a larger bed, but require a longer mattress than a twin because of their height or other needs.

Something that should be noted is that it can be a bit more difficult to find sheets for a Twin XL, as not every major sheet manufacturer produces all of their products in a Twin XL size. However, in the age of the internet and online shopping, it’s certainly simple enough to find a set of Twin XL sheets that meets your budget.

Using Two Twin XL’s on a King Frame

In addition to being perfectly usable as a mattress on their own, sometimes people choose to use two Twin XL mattresses to fill a king size frame. This is a popular solution for couples with dramatically different sleep preferences or needs.

Moreover, two Twin XL mattresses are a good option for couples who want to get an adjustable bed frame. The benefit of this setup is that the sleepers can be in different positions, one sitting up and one laying down. This offers tremendous flexibility for those that have different sleep preferences or habits than their partners.

Full Bed Dimensions

A Full mattress, also known as a standard double, is probably the most common size of mattress. You encounter these mattresses in hotel rooms that have two beds in them, many guest bedrooms, and more. They’re a fantastic option for children of most ages, as we discuss in our guide to finding the best mattress for children.

A Full bed can fit two people, but it will be a tight fit. The dimensions of a standard double are 54” x 75” (W x L). A Full mattress is an excellent option for single sleepers especially those who like to spread out while they’re sleeping, or sleep diagonally across the mattress.

For individual sleepers, the bed offers 54” of space, but for two people there is only 27” of width for each person. You’ll notice that amount of room leaves you with about 1/3 of the space you’d get from a twin bed. 27” is just over two feet long, so couples really will be squeezed tightly on the bed.

The length of a full bed is also an important consideration. While most of the population will fit on to the mattress comfortably, those who are 6 feet tall will only have 3” of extra space at the end of the bed. This presumes that the tip of your head is on the very edge on the other end of the mattress. As a result, some sleepers may find that they are too tall to comfortably sleep on a full, especially with another person.

Queen Bed Dimensions

A Queen bed is a popular choice for couples, especially those on a budget or who have space limitations. It’s currently the most popular mattress size for individual mattress purchases. As a result, you can be confident that, no matter what kind of mattress you want, it will be available in a queen.

Queen beds are 60” by 80” (W x L). Therefore, it can comfortably sleep two people, two people and a small child, two people and a small pet, or one person and a large pet. It’s also the preferred size for single sleepers who are especially active.

The Queen mattress needs a bit more real estate than a full bed, and it’s advised that you only purchase a Queen mattress if the room it’s going in is at least 10 ft x 10 ft. It’s recommend for couples, active single sleepers, and those who share a bed with children or pets. Moreover, a 6’ tall sleeper will have 8” of space, so it might be more comfortable than they would be on a full bed.

King Bed Dimensions

A King bed is the second largest commercially available bed. A King mattress measures 76” by 80” (W x L). These measurements mean that each partner in a couple gets 30” of sleeping space, which is 8” less than you get from sleeping as an individual on a Twin mattress. However, it’s much more space than you get from either a Full or Queen mattress. 

A King bed is ideal for couples, sleepers that really like to sprawl out on the bed, or those who share a bed with children or pets. In order to fit a King mattress in your room and leave enough space to get around and have the other items of furniture you’d want in a bedroom, your room should be at least 12’ x 12’.

Split King Bed Dimensions

A Split King is an excellent option for couples who have dramatically different needs from a bed. It uses two Twin mattresses, so each sleeper gets 38” of width to enjoy. This is the best choice if your sleeping needs are radically different from your partner’s needs. The two Twin mattresses that make up a Split King can have incredibly different properties. For example, one side might be very firm and the other side might be extra soft. This arrangement means that everyone can get the mattress they want or need.

California King Bed Dimensions

The largest type of commonly available mattress is a California King. This bed measures 72” by 84” (W x L). These dimensions make this bed the best option for sleepers who are exceptionally tall, or those who want to have the maximum possible space to lay on.

It’s important to note that while the California King is longer than a standard King, it is also narrower than a Standard King by 4”. Therefore, it is not the best option for couples that are looking to have the most room to sleep individually, or those with exceptionally wide frames.

What Size Mattress Do You Need?

In order to figure out what size mattress you need, you must account for the size of the room, who will be sleeping on the mattress, and the individual’s sleep preferences. We’ve put together this handy chart to help you quickly determine the best mattress for you.




Optimal For


38″W x 75″L

Toddlers, Children, Single Adults

Twin XL

38″W x 80″L

Children, Single Adults (tall), Sleepers who want to use an adjustable bed frame

Full (Double)

54″W x 75″L

Children, Single Adults, Single Adults with Children or Pets, Couples (small)


60″W x 80″L

Single Adults, Single Adults with Children or Pets, Couples


76″W x 80″L

Couples, Couples with Children or Pets

Split King

(2) 38″W x 80″L

Couples (with varying mattress preferences), Sleepers who want to use an adjustable bed frame