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Mattress Dimensions: How to make the right choice?!?
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Mattress Dimensions: How to make the right choice?!?

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Queen, King, Double, Simple, Cal King… Looking for the right mattress dimensions according to your needs? No worries, we're here to help you! Here is our complete size guide.

What Are the Standard Mattress Dimensions?

As you surely know, there isn’t just ONE mattress size, but MANY, and each corresponds to a particular sleeper situation!

Here’s a mattress dimensions chart to help you understand the difference and help you choose.


Dimensions (inches)

Dimensions (cm)

Perfect for


28” x 51”

71 cm x 129 cm

Newborn, toddlers.


38” x 75”

97 cm x 191 cm

Kids and adults that live in a small space, such as a student apartment, for example.

Twin XL

38” x 80”

97 cm x 203 cm

Taller students and teen bedrooms.

Double (Full)

54” x 75”

137 cm x 191 cm

Single adults that have or don’t have pets, and teens that sleep diagonally across their bed.

Double (Full) XL

54” x 80”

137 cm x 203 cm

Tall adults or adults with multiple pets.

Short Queen

60” x 75”

152 cm x 191 cm

Van lifers or people traveling in any type of RV.


60” x 80”

152 cm x 203 cm

Couples who want more space or who sleep with pets, and single adults that like to sleep diagonally.

Olympic Queen

66” x 80”

168 cm x 203 cm

Couples who like to have more free space. Great to welcome pets or sleep diagonally, but remain smaller than a king size.


76” x 80”

193 cm x 203 cm

Couples that like to have a lot of free space or to welcome their multiple pets. This mattress size is well suited for larger master bedrooms

Cal King

72” x 84”

183 cm x 213 cm

Couples that are taller than average, or couples who love to have an enormous sleep surface.

A couple sleeps peacefully on their Polysleep Mattress

Which Mattress Size is Best for Me?

Still not sure which mattress dimension will be the best fit for you? Here’s more information about each size.

Crib Mattress

The crib mattress standard size 28” x 51” (71 cm x 129 cm) is perfect for a newborn or a toddler. Your child will usually need a bigger mattress between the age of 18 months and 3 years ½ (this varies for each child).

Twin Mattress

Measuring 38” x 75” (97 cm x 191 cm), this mattress is above all intended for children and young adults. In that sense, this mattress is perfectly suitable for single people and students, who often live in apartments or share one. The Twin is appropriate for bedrooms with limited space, from 7 x 10 feet (18 cm x 25 cm).

On the contrary, if you’re tall, live with a spouse, or like to spread out when you sleep, you should forget this solution right away. Unless you like to sleep very close to one another.

Minimum recommended room size: 7’ x 9’ (2,15 m x 2,75 m).

Twin XL Mattress

This bed size features an increased length compared to its standard counterpart, and therefore culminates at 38” x 80” (97 cm x 203 cm). It’s a great mattress size for university students because it fits most post-secondary dorm beds.

This mattress size can be installed in a confined space, but still offers more length for those who are taller. It’s also the ideal solution for a teenager’s bedroom.

This size is suited, just like its twin mattress counterpart, for student apartments and shared apartments. It is, however, by no means appropriate for couples or for those who like to take up a lot of space while sleeping.

Minimum recommended room size: 8’ x 10’ (2,45 m x 3 m).

Double (or Full) Mattress

This mattress, presumably for two people, isn’t in fact the best pick for two. In truth, it only provides one more inch in width compared to the two types of Twin mattresses mentioned above.

Those mattress dimensions were the standard in use for couples’ beds a few decades ago, when houses were built with smaller bedrooms. This format is now used to accommodate single adults and teens that really want to spread out on the whole bed when they sleep. It can also help if you’re looking to put a bed in a smaller guest room.

So it’s perfect for all kids, teens, or adults who want more personal space, or who sleep in the company of their pet. It can also suit couples that like to cuddle when they sleep and aren’t afraid to raise the temperature.

But it’s not a size recommended for couples who require a certain personal space to spread their legs or who move around a lot. It is also not recommended for taller adults or for couples who can’t sleep without their cat (or their dog).

A full mattress measures 54” x 75” (137 cm x 191 cm).

Minimum recommended room size: 10’ x 10’ (3 m x 3 m).

Double (or Full) XL Mattress

This mattress size is as wide as the standard double mattress but gets 5 more inches in length. In the end, this makes a 54” x 75” (137 cm x 203 cm) mattress.

Those mattress dimensions are great for taller single adults that like to sleep alone or with a pet.

Minimum recommended room size: 10’ x 11’ (3 m x 3,35 m).

Short Queen Mattress

The short queen mattress dimensions will fit most RVs. 60” wide by 75” long (152 cm x 191 cm), this mattress is as wide as a regular queen mattress, while being 5 inches shorter. This helps the mattress fit in places where there’s less room available.

If you’re planning to go on an adventure in your motorhome, your caravan, your travel camper, or your custom-made travel van, this is the mattress you should get!

Minimum recommended room size: 9,6’ x 10’ (2,95 m x 3 m).

Queen Mattress

The Queen mattress is the most popular in terms of sales, and that makes sense: it offers a greater length for tall adults and significant additional width. So couples can cuddle while sleeping and also give each of them more personal space to move during the night.

This mattress measures 60 inches in width for 80 inches in length (152 cm x 203 cm).

While it is great for couples, it can also be perfect for single adults who like to spread out on the whole bed surface, or who want the company of their pet(s). If you are looking for a two-person bed AND would also like to sleep with your dog and/or your cat, then maybe you should opt for something bigger.

Minimum recommended room size: 10’ x10’ (3 m x 3 m).

Olympic Queen Mattress

6 inches wider than a standard Queen mattress for an equivalent length (66” x 80” — 168 cm x 203 cm), the Olympic Queen mattress dimensions offers more room for each of its occupants, and even allows you to add your dog or your cat to the equation, without having to invest in a King size mattress.

This way, if having more personal space is important to you as much as to your spouse, the Olympic Queen is a mattress size to consider. It’s also great if you like to sleep with a mountain of pillows, which undoubtedly will take up more room. It’s also an especially suitable mattress if your room is long enough for a king mattress but not wide enough.

Minimum recommended room size: 10’ x10’ (3 m x 3 m).

King Mattress

This mattress type is the equivalent in size of two Twin mattresses placed side by side.

With a King mattress, you, your spouse, and your rottweiler will sleep in unparalleled comfort! The King mattress is very large (76” x 80” — 193 cm x 203 cm), so each of its occupants obtains more than enough personal space.

This mattress dimension is perfect for a larger master bedroom (ideally 10’ x 12’ — 3 m x 3,65 m — or larger).

Minimum recommended room size: 10’ x 12’ (3 m x 3,65 m).

California King Mattress

The California king mattress (a.k.a. “Cal king”) is actually the same size as two Twin XL mattresses placed side by side. It measures 72 inches wide by 84 inches long (183 cm x 123 cm).

This mattress size is particularly appropriate if your couple is taller than average, or if you like to enjoy a lot of personal space. It’s also perfectly suited if you want to spend your nights with all your furry friends, whether dogs or cats.

It’s the cream of the crop, as long as your bedroom is large enough to fit one!

Minimum recommended room size: 12’ x 12’ (3,65 m x 3,65 m).

Why Is It Important to Get the Right Mattress Size?

Two kids are playing with their parents and jumping on the Polysleep Mattress

A mattress size, as the materials used in its manufacture, is a crucial element to determine your comfort. Considering that a human being spends on average ⅓ of his/her life on a sleeping surface, choosing well is of great importance in anyone's life.

1 - You Don’t Want to Sleep in an Inadequate Position

A mattress that is too small for you —and eventually your significant other— can cause you to sleep in an inadequate sleep position and create physical discomfort.

If you’re taller than said mattress dimensions, many things can happen and make you feel bad in the morning:

  • Your legs and/or your head could eventually end up hanging over nothing;
  • Additional stress can be caused on multiple pressure points;
  • You risk waking up stiff with sore muscles, even joint pains;
  • Your muscles won’t have enjoyed optimal rest during your sleep. Same thing with your bones;
  • You could then wake up in the morning with some physical tiredness, or feeling even more tired than the night before.

Sleep should be for resting, not to feel more tired!

2 - It Will Influence How Many Occupants (Humans or Animals) Can Sleep in It

Are you a single person with a cat (or two, or a dog)? Or you’re sharing your life with a significant other (maybe with kids)? Well, there’s no doubt that your love and family situation needs to be taken into account.

If you live with a significant other, it goes without saying that opting for a Twin mattress is almost impossible! This might work for a kid, a teen, or even an adult with a small apartment, but this won’t work for a couple.

And on top of that, if there’s a cat that tries to hoard its own space… You can simply say goodbye to having a good night’s rest.

So, you will have to take into consideration the space required for every passenger before your departure to dreamland, so that everybody has enough personal space (cat included).

That’s how you’ll avoid any involuntary night-time “surprises” from your partner or your feline, such as an unintended slap from them when they’ll move during their sleep.

3 - The Bed Can Become Unpleasantly Hot

What is more, if you’ve chosen a bed that’s too small for your couple, you’ll be crammed together, which can reduce your bed’s capacity to disperse heat.

As much as you can like it during winter, this can become troublesome in summer when the mercury rises. After a while (perhaps not very long during a heat wave) you will pray for a more ventilated bed.

So you should choose the size of your mattress with this fact in mind.

4 - Beds (And Mattress) Do Not Fit In Every Bedroom

Finally, you should choose your mattress based on the size of your bedroom, just like you did for your bed base. Because to be able to sleep in your room, you should first be able to enter it!

Too large of a bed in a small room won’t fit. And even if it does, you won’t be able to freely move around as you need.

So make sure to properly measure your room and then, choose your bed and mattress dimensions accordingly.

Choosing The Right Mattress Thickness According to Your Morphology

A woman sitting cross-legged on her Polysleep Mattress stretches her back

There is a misguided notion that the larger the mattress, the thicker it should be. That's a misconception since most models actually for sale propose the same thickness no matter the selected mattress’ dimensions.

Why? Because different thicknesses of mattresses can also be offered depending on the weight of the sleepers.

Therefore, some manufacturers offer various thickness options for each of their mattress models! While mattresses are available in thicknesses ranging from 6 to 18 inches (15-46 cm), most of them have a depth of 8 to 12 inches (20-30 cm).

To choose the right thickness for you, your sweet half, and maybe your whole furry family, you have to take into account how much each of you weighs. On that basis, sleepers are divided into three categories of weight, with each their recommended mattress thickness.

How Thick Should a Mattress Be?



Sleepers of less than 130 pounds / 59 kg.

The mattress thickness can be equal to 10 inches (25 cm) or less

Sleepers of 130 to 230 pounds (59 to 104 kg).

For acceptable comfort, the mattress thickness can be between 8 to 12 inches (20 to 30 cm). But a lot of these sleepers will prefer a thickness that rather lies between 10 and 12 inches (25 to 30 cm).

Sleepers weigh over 230 pounds (104 kg).

The thickness for sleepers with a greater stature should be at least 11–12 inches (28-30 cm). But the majority of them will favor a mattress thickness of over 12 inches (30 cm).

Lightweight Sleepers (130 pounds —59 kg— or less)

Lightweight sleepers, weighing less than 130 pounds (59 kg), will prefer a mattress with a thickness of 10 inches (25 cm) or less because it’ll offer adequate support without them sinking too much into the mattress.

Average Weight Sleepers (130–230 pounds —59 to 104 kg)

Sleepers with an average weight (between 130 and 230 pounds —59 to 104 kg), for their part, will be comfortable on mattresses with a thickness of between 8 and 12 inches (20 to 30 cm), although most of them will prefer a thickness that lies between 10 and 12 inches (25 to 30 cm). These thicknesses really provide the perfect balance between comfort and support for most sleepers.

People with a large body type (230 pounds —104 kg— or more)

For heavier sleepers (230 pounds or more), a minimum thickness of 11–12 inches (28-30 cm) is essential. But most of them will prefer a thickness superior to 12 inches (30 cm).

These mattresses with increased thickness will not flatten out under their weight and offer all the support required by their non-standard stature.

Choosing The Right Mattress Dimensions May Take Time

The Polysleep Mattress size in a room

As you’ll have understood, choosing the right mattress dimensions is far from easy. Many factors need to be accounted for :

  • The number of sleepers (humans and pets) in the bed;
  • The size of the sleepers;
  • How old are the sleepers;
  • The sleepers’ desire for personal space;
  • The bedroom’s size;
  • Your body shape and your significant other body shape;
  • Etc.

So make sure to think about all of what is mentioned above, and you'll be sure to make the right choice.

And if you’re really afraid to make the wrong choice, just try a mattress in a box. Some mattress companies (like us!) give the possibility to test the mattresses right at home and return them if you’re not happy with how they fell.

So, there is no longer any reason to be afraid of making a mistake by buying the wrong mattress. You just have to try one of our Memory Foam Mattresses right at home!

Mattress Dimensions FAQ

What are the dimensions of a king-size mattress?

The dimensions of a standard king-size mattress are 76 inches in width and 80 inches in length.

What are the dimensions of a ¾ mattress?

A ¾ mattress, commonly referred to as a small double bed, is 48 inches wide by 75 inches long.

What are the dimensions of a crib mattress?

A crib mattress can be found between 51 to 53 inches in length and 27 to 28 inches wide.

What are the dimensions of a queen-size mattress?

The dimensions of a standard queen-size mattress are 60 inches by 80 inches, width x length.

What are the dimensions of a single bed mattress?

The dimensions of a single bed are 38 inches wide by 75 inches long.

What are the dimensions of a full mattress?

A full-size mattress is 54x75 inches.

What are the dimensions of a super single mattress?

A super single mattress is larger than an extra-large twin at 48 inches wide by 84 inches in length.

What are the dimensions of a twin bed mattress?

A standard twin size bed is 38 inches by 75 inches and an extra-large twin is the same width but 80 inches in length. A twin XL mattress is 38” x 80” inches.

What are the dimensions of an RV queen mattress?

A queen-sized mattress designed to fit an RV is 60 inches by 80 inches.

What are the dimensions of a short queen mattress?

A short queen mattress is designed to fit into a smaller space at 60 inches wide by 74 or 75 inches long.

Is the California King Bigger Than the King?

Well, yes and no. The California King Mattress (or Cal King), is 4 inches (10 cm) longer than the king but is also 4 inches (10 cm) narrower.

What Is the Difference Between a Twin and a Single Mattress?

Single and twin mattresses correspond to the same dimensions. Twin beds and single beds are both 38 inches wide and 75 inches long (97 cm x 191 cm). A single (or twin) mattress will be perfect for a growing toddler/child and small teenagers.

Are Full-Size Mattresses the Same as Double Beds?

There is no difference between a full-size and a double-size mattress. They both measure 54 inches by 75 inches (137 cm x 191 cm). Full-sized mattresses are actually 16 inches (41 cm) wider and 1 inch (2,5 cm) longer than twin-sized mattresses, so the name "double" comes from the idea that a full mattress is twice as big as a twin.

What’s the Most Popular Mattress Size?

Without a doubt, the queen mattress is the most popular. Because despite being large enough to fit most couples, it fits into an average-sized bedroom. The mattress is also a good choice for single people who need more space than a twin bed can provide.

Is a Double Bed the Same as a Queen?

No. The queen mattress is actually 6 inches (15 cm) wider and 5 inches (13 cm) longer than its double counterpart. On the other hand, the double (or full) XL is as long as the queen mattress but is still 6 inches (15 cm) narrower.

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