Mattress Size and Dimensions

A Buyer’s Guide to choosing the right mattress size for you and your bedroom

A good night’s sleep is essential for our health and wellbeing, and having the right size mattress is a crucial factor in achieving the rest we need. Whether you’re considering upgrading to a larger bed, downsizing to a smaller space, or simply looking for a better fit, understanding bed sizes and dimensions can help you make the right choice. From Twin to California King, each mattress size comes with its own set of pros and cons, and choosing the right one can make a significant difference in your sleep quality and comfort.

In this guide, we’ll explore the various bed sizes and dimensions available, discuss the factors to consider when choosing the right size mattress for your bedroom, and provide some tips on how to measure your space to ensure a perfect fit. Whether you’re sleeping solo or sharing your bed, this guide will help you choose the right size mattress for a comfortable and restful night’s sleep.


US Bed Sizes and Dimensions

Twin, Twin XL, Full, Queen, King, and California King bed dimensions

Every mattress is different; from the materials used, to how soft or firm they feel. Even the process of construction can differ quite a bit from bed to bed. In a side by side comparison, the most popular beds may seem to have more differences than similarities. Generally, however, they all share one common but very important factor in choosing the right mattress and that is the bed size and dimension.

Mattress Sizing Chart

Mattress sizes and dimensions can vary considerably around the world so if in doubt it’s always best to reach out to a company directly for exact sizing. Or browse our mattress reviews, where we include the dimensions for each bed in our purchase details.

In the U.S.A, there are voluntary dimensional guidelines that are set by the International Sleep Products Association (ISPA) which means that in most cases a mattress will keep the same dimensions no matter where you purchase from (unless otherwise stated).

Choosing Your Bed Size

So why does it really matter so much and what mattress size should you be choosing for your household? In many cases, bed size is a factor when it comes to fitting a new mattress into your space. You don’t want to end up making a room feel smaller than it is, but you also want a mattress large enough to accommodate your sleep needs.

Even if space isn’t an issue, going larger may or may not be the right choice. So, let’s talk about the standard US bed sizes and their dimensions to see who benefits most from each size. Choosing a bed size will depend on the following:

  • Space inside of the room
  • Body size & shape
  • Sleeping position
  • Single or shared

And of course, personal preference. While some couples may wish to sleep like kings and queens in a King or California King size bed, others may prefer the intimacy of having a Queen size mattress. On the other hand, those who sleep alone may enjoy the luxury of space a King size mattress provides. Still, others may find a King size bed much too big. Let’s break it down!

Related: Find & Optimize Your Best Sleeping Position

Twin Size Bed Dimensions

Best For Limited Space and Budget.

This is the smallest adult size mattress available and measures 38” W X 75” L. Twin size beds are most commonly used by those with limited space, but could also be suitable for a child that has simply outgrown their toddler mattress. Due to the size, it also makes it an excellent choice for those purchasing a mattress on a tighter budget.

This bed size is ideal for siblings sharing a room, bunk beds, guest rooms, and dorm rooms. The recommended minimum room size for a Twin size bed is 7 feet by 10 feet.

Twin Size Bed Dimensions and Mattress Sizing Chart

Twin XL Size Bed Dimensions

Best For Limited Space and Budget, Taller Folks.

The Twin XL shares the same width as the Twin size mattress but is 5” longer, measuring 38” W X 80” L. This is a great choice for those who are taller but don’t have space or the budget to go up a size to a Full size mattress. With a Twin XL, you won’t have to worry about your feet dangling off the edge of the bed!

Having exactly half the dimensions of a King size bed, 2 Twin XL’s can be combined on the same base or foundation to create a King size mattress. This makes the Twin XL an excellent choice for couples that have different feel and firmness preferences. For those using an adjustable base this is also a popular option if a Split King size mattress is not available.

The minimum room size for a single Twin XL mattress should be 9 feet by 9 feet.

Twin XL Size Bed Dimensions and Mattress Sizing Chart

Full Size Bed Dimensions

Best For Couples With Limited Space and Budget.

Full size beds offer a nice compromise between Twin and Queen size mattresses. Measuring 54” W X 75″ L they make a good choice for couples that don’t have a lot of space to spare or a single sleeper who prefers to roll around a bit more on a larger surface area. For some couples, this may still be considered a tight squeeze but could also be a great choice for those that like to snuggle or cuddle up with their partner.

Couples that opt for a Full size mattress will want to look for a bed that offers great edge support, allowing sleepers to utilize the full surface of the mattress and creating a more spacious feel. Innerspring and hybrid mattresses tend to offer better edge support than memory foam. At the same time, these mattresses typically provide better cooling and breathability which may be especially important when sharing such an intimate space.

The recommended minimum room size for a Full size bed is 9 feet by 9.6 feet.

Full Size Bed DImensions and Mattress Sizing Chart

Queen Size Bed Dimensions

Best For Couples, Medium Surface Area.

I like to refer to this as the happy medium, with dimensions measuring 60” W X 80” L the queen size bed is a nice step up from the Full size mattress. With a larger surface area, it is an even more popular choice for couples, or solo sleepers who share the bed with children or a pet. Larger individuals and/or those who prefer more room to move will appreciate the extra 6” in width that this mattress size provides.

The Queen is one of the most popular bed size purchases. Slightly larger than a Full size bed, the recommended minimum room size for a Queen size mattress is 10 feet by 10 feet.

Queen Size Bed Dimensions and Mattress Sizing Chart

King Size Mattress Dimensions

Best For Couples, Large Surface Area, Luxury.

The dimensions of a King size mattress are 76” W X 80” L making it one of the largest surfaces available for sleepers. A popular choice for couples who prefer a bit more room to spread out, a King size mattress is also an ideal choice for families, providing plenty of space for kids and/or pets to come and snuggle. Ultimately, whether you sleep solo or share your bed with someone else, a King size bed is sure to provide a luxurious sleep experience.

To comfortably fit a King size mattress the minimum recommended room size is 12 feet by 12 feet. This allows enough space for nightstands on either side and for easy movement around the bed.

King Size Bed Dimensions and Mattress Sizing Chart

Split King Size Mattress Dimensions

Best For Couples With Different Sleep Preferences or For Those Using An Adjustable Base.

In many cases, a Split King is actually one bed with only the top half of the mattress split. This is an especially popular choice for couples that are using an adjustable base but who share the same preference for firmness and feel. The Split King allows sleepers to make independent adjustments to each side of the base. Having this adjustability, for example, can allow for one sleeper to sit upright for reading while their partner may prefer enjoying a zero-gravity setting.

The Split King can also be created by placing 2 Twin XL’s together to form a King size mattress. As we mentioned earlier, each Twin XL bed is equal to exactly half the dimensions of an Eastern King bed. This is a popular choice for couples who have very different sleep preferences and struggle to find a mattress that suits both sleeper’s needs. With a Split King, each sleeper can choose the bed that is best for them but still enjoy the experience of sleeping together. Ultimately, the Split King is all about customization and independence for each sleeper.

*If you don’t like the idea of a split down the middle of the bed, but still want a high level of customization, we recommend an adjustable air mattress. Also available in Split King options, adjustable air beds allow sleepers to independently adjust the firmness level of their side of the bed.

California King Size Dimensions

Best For Couples and Taller Folks, Large Surface Area.

A California King mattress, like the King size bed, has a large surface area with dimensions measuring 72” W X 84” L. Slightly narrower than an Eastern King bed by 4 inches, the California King mattress gains 4” in length, making it a wonderful option for taller sleepers or those of you with pets that like to sleep at the base of the bed. Sheets for a California King mattress can be more difficult to find and often more expensive than standard King size sheets so keep this in mind before deciding.

The slightly longer dimensions of the California King size bed are best suited to a minimum room size of 12 feet by 12 feet.

California King Size Bed Dimensions and Mattress Sizing Chart

Alaskan King Size Dimensions

Best For Couples, Taller Folks, Extra Large Surface Area.

An Alaskan King Mattress is a non-standard, custom-sized mattress that measures a whopping 108″ W X 108″ L making it significantly larger than a standard king-sized mattress. The extra size of an Alaskan King Mattress provides ample room for stretching out and ensures that both partners have enough space to sleep comfortably. Commonly referred to as a family bed, it can comfortably fit four adults. However, due to its non-standard size, finding bed linens, bed frames, and other accessories to fit an Alaskan King Mattress can be challenging, and it may not comfortably fit in all bedrooms or even through all doorways. 

Naturally, the dimensions of an Alaskan king-size bed are best suited for a larger room. We would suggest a minimum room size of 16 feet by 16 feet.


Which Bed Size Is Right For You?

As you can see there are many deciding factors when choosing a mattress size for your space. For children and young adults a Twin, Twin XL, or even a Full size mattress is an excellent choice.

While single adults may be most comfortable with a Twin XL, Full, Queen, or even a King size mattress for the most amount of surface space. A Queen, King or California King size bed is most comfortable, for couples, but if budget and space are a factor you could opt for a Full size bed. Just make sure you enjoy cuddling with your partner as it will be a tight fit for some taller or larger couples. After all, Full size mattresses were the norm for couples once upon a time.

Choosing a King, California King or Split King Size Mattress

If budget and space are not a deciding factor, both the King and California King size mattresses provide plenty of space and luxury. While both these styles are great if you share your bed with children and/or pets, the California King size bed is the clear winner for taller individuals. For those under 6 feet tall, you may prefer the additional 4” in width that the standard King size mattress provides.

Lastly, for couples who have very different sleep preferences, we recommend purchasing two Twin XL size mattresses. Together, these beds can be placed on a frame or adjustable base to create the same surface dimensions of an Eastern King size bed. Like the Split King option, 2 Twin XL size beds can be used with an adjustable base allowing each sleeper to independently adjust their side of the bed. This is truly the best option for couples who like a lot of customization.


There is no real right or wrong answer when it comes to choosing a mattress size. Room-scale, body type, and preference are just a few of the deciding factors in choosing what best suits you and your family. Once you understand the pros and cons of each choice given to you, you can be confident in making a decision on your next mattress purchase, without the worry of whether it will fit into your bedroom.