Mattress Sizes and Dimensions: Which Bed Size Is Right For You?

After years of late nights together, the day to say goodbye to your old mattress has come. Whether they provided you with years of cozy and comfortable nights or rewarded your time together with an endless supply of backaches, it’s time to move on to bigger and better beds.

But choosing the right bed size isn’t for the faint of heart. You’re making a long-term commitment to a mattress that’s the perfect size for your needs.

Beyond personal preference, several factors should be considered before picking a mattress size. You’ll want to consider the size of your bedroom, who you’ll be sharing your bed with, and how much available space you have.

Mattress Size Guide

Mattress Size Guide

In this mattress size guide, we illustrate the mattress dimensions of all six standard mattress sizes—and some of the lesser-known options—to help you choose the best mattress for your needs. 



Dimensions: 38” x 75”

A twin mattress is the smallest traditional bed on the market at 38 inches wide and 75 inches long. Its compact footprint makes it ideal for single sleepers — either children or adults with small spaces like a studio apartment.

Best for: kids, bunk beds or single sleepers.

Room size: The minimum room size for a twin bed to fit naturally is 7 x 9 feet. But if you’re looking to outfit the room with cozy accessories like a desk and dresser, an 8 x 10 square foot room may be required for the bed to fit more comfortably.

Twin XL

Twin XL

Dimensions: 38” x 80”

The twin’s slightly longer cousin, the twin XL mattress, is the most popular size for college dorm rooms. It measures five inches longer than a twin, at 38 inches wide and 80 inches long. In addition to students, XL twin beds are a good solution for taller teenagers and individual adults with limited space. These beds can also be put together if you’re choosing a split king adjustable base for full body adjustability!

Best for: taller teenagers, single adults or anyone with limited space.

Room size: The minimum room size for a twin XL mattress to fit naturally is 8 x 10 feet. Twin XL beds can also work well in narrow rooms that are at least 7 feet wide.



Dimensions: 53” x 75”

The full mattress is a good starter mattress for young adults or recent grads living on their own for the first time. Sometimes called a double, the full is 16 inches wider than a twin at 53 inches wide and 75 inches long. A full is not recommended for couples who like to share the bed with pets or their children or enjoy sleeping like starfish. However, it is a smart choice for guest rooms or couples who enjoy a solid night of snuggles.

Best for: young adults, couples who like to cuddle or guest rooms.

Room size: The minimum room size for a full bed to fit comfortably is 10 x 11 feet.



Dimensions: 60” x 80”

The most popular mattress size on the market is the queen mattress, which is traditionally used in a master bedroom. At 60 inches wide and 80 inches long, the queen mattress size offers plenty of space for couples or individuals who like having extra room to move around in bed. They’re also an excellent choice if you’re the proud owner of a small- or medium-sized furry friend who appreciates the value of a supportive mattress.

Best for: couples or adults who like to sprawl out.

Room size: The queen mattress fits best in a master bedroom that is at least 10 x 10 feet.



Dimensions: 76” x 80”

At 76 inches wide and 80 inches long, the king mattress is large enough to accommodate couples who share the bed with their children or a sizable pet (think: a Great Dane). A king bed can be made of two twin beds pushed together, which is referred to as a split king. King beds are large enough that both sleepers can sprawl out with room to spare.

Best for: couples who enjoy their sleeping space or share a bed with children.

Room size: A king mattress fits best in a spacious master bedroom, preferably at least 12 x 12 feet.

California King

California King

Dimensions: 72” x 84”

The longest standard mattress on the market, the California king mattress measures a whopping 72 inches wide and 84 inches long. Its generous length makes it ideal for taller individuals, especially people more than six feet tall. Of course, people of average height might also benefit from a California king depending on how many people and pets are sharing the bed.

Best for: Couples with kids or four-legged friends who want a luxurious amount of sleeping space.

Room size: A California king mattress fits best in a large master bedroom of at least 12 x 12 feet.

Which Bed Size Is The Best For Me?

If it’s time for a new mattress, you may be wondering which size is right for you. There are many factors to consider, like who will be sleeping in the bed, how much space you will need, how much room is in your bedroom, and any specific health or sleep issues you might face.

Buying a new mattress is not a one-size-fits-all situation, so it’s essential to evaluate your individual needs. If you have a history of back pain or sleep problems, you may want a free trial period to help you make sure you’re comfortable with your new mattress.

Here are some other major factors you will want to consider when choosing a mattress.


Who Will Sleep In the Bed

Will you be sharing the bed with a partner? Do your children or dogs typically sleep with you? These are questions to ask yourself before deciding on mattress size. Typically twin, twin XL, and full mattresses are meant for one person. On the other hand, queen, king, and California king beds are a good bed size for couples and any children or pets that wander into the bed in the middle of the night.

If you are going to sleep with another person, consider how close you like to sleep. If you both enjoy stretching out when sleeping, the extra room afforded by a king or California king size will be appreciated—and help you avoid any accidental thwacks if your partner rolls over in their sleep.

Your Room Size

The amount of space available to you should also be considered. A larger mattress will take up more space in your bedroom, as will any other bedroom furniture, so you will need to plan accordingly.

To help you decide if there is ample space for the mattress you’re considering for your room, here is a bed size dimensions chart in square inches and square feet:

  • Twin: 2,925 sq. in./20.3 sq. ft.
  • Twin XL: 3,120 sq. in./21.7 sq. ft.
  • Full: 4,050 sq. in./28.1 sq. ft.
  • Queen: 4,800 sq. in./33.3 sq. ft.
  • King: 6,080 sq. in./42.2 sq. ft.
  • California King: 6,048 sq. in./42 sq. ft.

Your Body Size

You should take your height and width into consideration when choosing a mattress. A typical twin mattress is 75 inches long, while a twin XL is 80 inches long. If an individual is taller than six feet two inches, a twin mattress is probably not for them. Instead, it’s best to go with the XL, full, queen, or king bed, all of which can accommodate someone who is up to 6 feet 7 inches.

Those that are taller than 7 feet should opt for a California king bed. For those who want more space on either side of their body, a full, queen, or king bed will be the most comfortable.

Your Sleep Position

When narrowing down your mattress size choices, consider how much space you’ll need to comfortably move around while you sleep. Do you toss and turn like a cowboy riding a bronco, or do you more closely resemble a hibernating bear who doesn’t move once you close your eyes?

You could be a side sleeper, a back sleeper, a stomach sleeper, or a combination of the three—most people are. If you know you do a lot of sleep-riddled moving and grooving as you sleep, a wider mattress might be a better choice for you.

Your Budget

The amount of money you are willing to spend on a mattress can also help you choose the right size. A king will cost more than a queen size, and a queen more than a full, etc. Buying a mattress that meets both your size needs and your financial needs is key.

Of course, there are other factors that determine the price of a mattress, including:

Materials – The materials that manufacturers use to make their beds play a big role in deciding the final price of a mattress. For example, innerspring and all-foam mattresses are a more cost-effective option if you’re on a budget. In contrast, latex and hybrid beds use more high-end materials and can cost twice as much but are more durable and provide ample comfort and support.

How you buy it – Nowadays, when it comes to shopping, many people prefer to make their purchases online. However, mattresses are often the exception to the rule because it’s helpful to get a real feel for the bed before you commit to purchasing it.

That said, there are also real advantages to shopping online. According to the Sleep Foundation, some brick-and-mortar stores actually mark up the cost of their mattresses by up to 900%. In contrast, online retailers have less overhead costs and can often sell their products at a more affordable rate, saving you some valuable dollars in the process.

What Are Some Less Common Mattress Sizes?

While six traditional mattress sizes may feel like plenty of options to choose from, sometimes you want something a little less traditional.

Perhaps you have very distinct personal preferences. Maybe the size and shape of the room you’re decorating requires something more unique.

Whatever the reason, there are numerous lesser-known mattresses (aka specialty sizes) available. From the “small single” to the gargantuan “Alaskan King,” here are some of the specialty mattress sizes and their bed size dimensions:

  • A small single is 30 x 75 inches. This pint-sized bed is inches narrower than a twin-size bed. The small single bed is ideal for little tykes who’ve just graduated from the crib or for families trying to save space in a smaller room.
  • A super single is 48 x 84 inches. While it’s not quite as wide as a full-size bed, its elongated length of seven feet is significantly longer than a full bed. Its length even outstretches a king-size mattress, making the super single the ideal bed for a taller-than-average teenager.
  • A full XL is 53 x 80 inches. The XL full mattress offers the same width as a standard full but generously gives tall sleepers five inches of extra space to stretch to their full capacity.
  • An RV Queen is 60 x 75 inches. Just five inches narrower than a standard queen, this is the perfect replacement for most queen-sized mattresses in an RV (where bedrooms often give the word “cozy” a new meaning).
  • An Olympic queen is 66 x 80 inches. At six inches wider than your average queen-size bed, this mattress is perfect for couples who want more space but may not have a big enough room to comfortably fit a king-size mattress.
  • An RV King is 72 x 80 inches. Like its royal companion, the RV queen, the RV king is a sound choice if you’re looking to purchase a new mattress for your RV that more comfortably complements the small bedroom where it’ll reside.
  • A Texas King is 80 x 98 inches. They weren’t lying when they said everything is bigger in Texas—and that includes mattresses. For sleepers interested in sprawling from head to toe (and then some), the Texas King may be the bed you never knew you needed. At a little over eight feet long, it also wins the honorary title of “longest specialty bed”.
  • A Wyoming King is 84 x 84 inches. While it may not be as long as the Texas king mattress, it is a perfect square at exactly 7 x 7 feet. Because of their perfectly symmetrical shape and large size, placing them in a bedroom with a minimum of 12 x 12 feet will offer a more comfortable and contemporary fit.
  • An Alaskan King is 144 x 84 inches. The Texas king has nothing on this mammoth of a bed. At 12 feet wide, it’s a picture-perfect mattress for an enormous-sized room. Whether you have a big family who loves movie nights in bed or you’re looking for a visually-pleasing solution to an extra (extra) large master bedroom, an Alaskan king certainly won’t disappoint.

How to Find the Right Bedding for Your Mattress

Once you’ve found a mattress that checks off all of your must-have boxes, it’s time to treat yourself (and it) to bedding that pairs perfectly with your bedroom’s current aesthetic.

But what exactly does bedding consist of?

Generally speaking, the term bedding includes some of the fundamental accessories for your bed, like:

  • Sheets
  • A bedspread (usually a comforter, quilt, or duvet)
  • Pillows
  • Pillow covers
  • Extra blankets
  • A mattress cover
  • A bed skirt

Sometimes our need for instant gratification gets the best of us and we buy the first duvet and set of sheets we come across. But you can ensure your new sheets are the perfect fit for any mattress by considering these helpful tips and tricks to find the bedding that’s right for you:

  • Breathability – Think about your current weather conditions and climate. If you live in a warmer environment or are prone to becoming a human furnace while you’re sleeping, a set of Hyperlite sheets allow optimum breathability so you’ll sleep like a baby feeling cool and comfortable all night long.
  • Comfort – While you may have heard that a higher thread count makes for softer and more luxurious sheets, the ideal thread count for high-quality cotton sheets sits between 200 and 400.
  • Hypoallergenic – You may be tempted to purchase the same all-natural 100% down duvet that your best friend can’t stop raving about. But if you have allergies or are sensitive to certain materials, a duvet filled with alternative stuffing, like the Down-Alt Duvet filled with 100% polyester, might be more your style.
  • Quality – Rather than clicking the “buy now” button only to realize too late that there’s no turning back, think long and hard about the quality of bedding that piques your interest. Just because you laid eyes on a comforter that complements your bedroom’s wall color doesn’t necessarily mean it’s the right bedspread for you. Instead, here are some aspects of your potential bedding’s quality to consider before making the final decision:
  • Material – Whether you’re shopping for sheets or a duvet, the quality of your bedding once again comes down to the thread count of the material. Somewhere around 250 is the sweet spot.
  • Filling – If you’re shopping for a duvet, look for options with more fill power (aka, more down or more alternative down). They often last longer than those made with smaller clusters of fill.
  • Weight – Some duvets are significantly heavier and therefore more insulating than others. When purchasing new bedding, consider your current climate to make sure you’re buying materials that aren’t too hot and aren’t too cold—they’re just right.

Find a Mattress Made Just for You with Casper

Finding the perfect mattress isn’t as easy as picking a new button-down for an upcoming date night. Like any relationship, it takes time, patience, and an understanding of what you want to find the one.

Whether you ultimately decide on a full-size, a king-size, or something in between, Casper is here to provide you with a mattress you’ll love just as much in five years as you do the day you bring it home.

From our most popular Original Mattress to the cooling Wave Hybrid Snow, you can choose from a variety of high-quality mattresses available in sizes ranging from twin to California King to fit your room no matter its dimensions.

Browse our collection to find your perfect match today.

Frequently Asked Questions

Assessing your options when it comes to choosing a mattress can be confusing, especially for those who don’t know the lingo. To help you with your search, here are some questions we hear frequently from our customers.

Mattress Dimensions FAQs

A single mattress and a twin mattress are one and the same — both have the dimensions of 38 inches by 75 inches. These, along with the twin XL (which is a little longer), are designed to fit one person.


The term “twin” came about because these mattresses were often placed two to a room, either in children’s rooms, hotels, or other rooms that are meant to be shared by more than one person.

A twin, also known as a single mattress, is the smallest size available on the market today. Casper twin mattresses are 38 inches by 75 inches and are the perfect size for a child or short single sleeper. Single sleepers that need a longer bed can try a twin XL, which is 80 inches long.

Although a twin XL is 15 inches narrower than a full, it’s 5 inches longer. Twin XL beds usually can’t comfortably accommodate more than one person, but they are an ideal choice for a single sleeper that’s too tall for a traditional size bed. Twin XL beds are great for small, narrow bedrooms where there’s not a lot of floor space, and are often the bed of choice for college dorm rooms and apartments.

The dimensions for a Casper double size mattress and a full mattress are 53 inches by 75 inches. In this case, both names represent the same kind of mattress. This bed is on the smaller side, but still able to fit two people if needed.

The full-sized bed (also known as a double) can fit two people. In fact, full mattresses were the most common size used by couples in the 1960s. They are advantageous because they are able to fit into smaller rooms. However, many adults these days prefer a larger bed.


The full bed is 53 inches by 75 inches, leaving only 26.5 inches across for each person’s personal sleeping area. The slightly larger queen bed offers 30 inches of space per person, while a king offers 38 inches per person. Depending on you and your bed mate’s sizes and sleeping styles, you may consider a queen or a king rather than a full.

Full vs. queen size beds are some of the most common choices for adult bedrooms. While a full measures 53 inches by 75 inches, a queen measures 60 inches by 80 inches. Full beds are good for young adults, couples who cuddle in their sleep, and guest rooms, while queen beds are an ideal bed for people who like to sprawl out at night.

If you’re deciding between a king or California king, it all comes down to four inches. A king mattress is actually four inches wider than a California king, while a California king is four inches longer than a king at 72 inches by 84 inches.

The king-sized bed is the widest bed that Casper sells, measuring at 76 inches by 80 inches. Those looking for a longer bed can purchase the California king, which is slightly longer and narrower, measuring 72 inches by 84 inches. Both beds should be large enough to fit two adults, although those who are taller may prefer a California king.

To determine the dimensions of a mattress, measure it from head to foot for the length and from side to side for the width. It may be helpful to measure the depth of the mattress as well, from the bottom where it rests on the box spring to the top.

You will want to use a tape measure and record these three dimensions, in inches, and repeat if necessary if you use a foundation. It’s important to measure your mattress and box spring before buying an encasement or bed.

Now that you know all about the sizes and dimensions of different beds, you should be able to make an informed decision regarding your next mattress. Once you have your sizing figured out, consider an adjustable bed frame for the ultimate comfort or some soft, breathable bedding to outfit your new investment!