Mattress Sizes: Tips For Knowing Which Bed Size Will Work For You

Mattress sizes may seem a mundane topic; one of those adult things that you will need later in your life.

But understanding all the different mattress sizes and which one works for the people in your life will help you create a more comfortable home.

Mattress Sizes

It will also help you avoid mistakes that will cost you later on by knowing the right bed size in order to make the best decision when you are faced with it.

Common Mattress Sizes and Dimension Chart

Mattress SizeDimensions in InchesDimensions in Centimeters
Small Single30" X 75"76.2 X 190.5cm
Twin Size Bed38" X 75"96.5 X 188.0cm
Twin XL Size Bed38" X 80"96.5 X 203.5cm
Full-Size Bed54" X 75"134.5 X 190.5cm
Full XL Size Bed54" X 80"137 X 203.5cm
Queen Bed Size60" X 80"152 X 203.5cm
Olympic Queen Size Bed66" X 80"167 X 203.5cm
King Size Bed76" X 80"193 X 203.5cm
California King Size Bed72" X 84"183 X 213.5cm

Some of the most important factors to consider when buying a mattress are the size of the room, the people who use the bed, and the available space in the room.

Added to these considerations, you also need to consider the price and your preferences for space in the bed.

Considerations Before Purchasing a New Mattress

Here is a list of some of these questions to ask yourself before you make the investment in a new mattress.

  1. Number of bed occupants – Who will be sleeping in the bed and will this change from season to season? This is something that may change over time when you consider extra children and pets that may occupy the bed during different seasons. Some people love co-sleeping with their children and want a larger bed to make this option available.
  2. Room size – How large is the room where the bed is located and could this change? You want the bed to look proportional with the room, i.e. not too large or too small for the space. It is best to have at least 2 feet on either side of the bed so as not to inhibit movement.
  3. Size of the people in the bed – What is the size of the people who occupy the bed? The bed should be at least 4 inches longer than the tallest person in the bed.
  4. Future use – Is this a bed that your child will be taking away with them at some future date? If this bed needs to fit a dorm room or a small apartment at a future date, a twin sized mattress would be a better option than a queen size bed.
  5. Preferences – Do you have a certain preference for how the bed looks in the room or for how much room is around you when you sleep? Preferences are important in considering bed sizes. You may want a larger bed even if you don’t need it. Also, you may like the look of one sized bed over another.
  6. Budget – Which size mattress works best within your budget? Larger mattresses are more expensive than smaller mattresses.
  7. Sleeping positions – Which sleeping position do the bed inhabitants prefer? Certain positions require larger mattresses. The width of the mattress should fit the person in the bed if they put their hands under their heads.

Small Single Size

Small Single Mattress Size

Small single mattresses are 30”wide and 75” long. This is a bed size that is ideal for young children who are first getting used to being in a “big bed”.

This size bed will not be appropriate for children as they grow, so it is not the best long-term mattress option.

  • Ideal Room Size: 7’x 10’

Twin Size Bed

Twin Size Bed

A twin sized mattress is 38” wide and 75” long. This is the smallest standard-size mattress available. This sized bed works well for children, teenagers, and people who live in small accommodations.

These are also cost-effective option that you can change out with more ease. Children can take this mattress off to a dorm or to a new living accommodation easier than with a larger mattress.

  • Ideal Room Size: 7’x 10’ (one twin) – 10’x 10’ (two twins)

Twin XL Size Bed

Twin XL Size Bed

A twin XL mattress is 38” wide and 80” long, so this mattress is as wide as a standard twin mattress but 5” longer.

This is a great mattress size for a taller child or teenager. Also, according to The Atlantic, this is the size that is most standard for college dorm rooms in the United States.

This bed also works best for adults who are limited with regards to space. Two of these sized mattress can also be put together to form a split king size bed with an adjustable frame for different sleeping needs.

  • Ideal Room Size: 7’x 10’

Full-Size Bed

Full Size Bed

The mattress dimensions for a full-size bed are 53”-54” wide and 75” long. A full-size mattress is also known as a double-size mattress.

This mattress is a good size for people who are just starting out. It provides ample space for one person, but is a tight sleep for two adult-sized people.

It is not the best option if the beds need to hold more than two sleepers, but it is an adequate choice for a guest room.

  • Ideal Room Size: 9.6’x 10.6’ – 10’x 12’

Full XL Size Bed

Full XL Size Bed

The size of a full XL mattress is 53”-54” wide and 80” long. This mattress is the same width as a standard full size mattress but 5” longer.

This is ideal if you need a smaller mattress but you are a tall person who needs the extra length. This also works well for two children or teenagers who are small in size.

  • Ideal Room Size: 9.6’x 10.6’ – 10’x 12’

Queen Bed Size Mattress

Queen Bed Size Mattress

A queen sized bed measures 60” wide and 80” long. This size is the most popular on the market because it is considered not too small but not too big.

This bed allows two people to sleep together with space between them. You also have enough space to add in an extra guest like a pet or a child as needed.

A queen sized bed works well in a guest room. It fits most standard size rooms.

  • Ideal Room Size: 10’x 10’ – 10’x 14’

Olympic Queen Size Bed

Olympic Queen Size Bed

An olympic bed queen size measures 66” wide and 80” long. It is 6” wider than your average queen size bed.

This size works well for families with small children who rotate in and out of the bed at different seasons.

It is just a bit wider to accommodate a larger crowd when needed but not too wide that it doesn’t fit well in a standard room.

  • Ideal Room Size: 10’x 10’ – 10’x 14’

King Size Bed

King Size Bed

A king size bed measures 76” wide and 80”. This is a full 16” wider than a standard queen bed. This size mattress works well for two people who like room to spread out or for co-sleeping with children or pets.

This size bed can be made up of two twin XL mattresses if you prefer to have a split bed arrangement where each side has different densities.

  • Ideal Room Size: 10’x 12’ – 13’x 13’

California King Size Bed

California King Size Bed

A California king size bed measures 72” wide and 84” long. This is the largest standard mattress that you can find on the market today.

This is a great bed for extra large bedrooms where you need a definite focal point. They are also great for co-sleeping families or for the odd family movie night.

  • Ideal Room Size: 12’x 12’ – 14’x 12’


Are the sizes in the USA standard for mattress sizes in other countries?

No, bed sizes vary across countries and each country has different wording and measurements for their mattresses.

For example, some countries refer to single and double beds while the US uses the terminology of a twin and a full bed.

Other countries measure by centimeters and the US measures in inches or feet. When you are ordering a mattress online, make sure you understand where it is coming from and its dimensions of beds before you purchase it.

What are the standard US mattress sizes in square feet?

A twin bed measures 19.7 sq. feet, a twin XL 21 sq. feet, a full bed 27.4 sq. feet, a queen bed is 33.1 sq. feet, a king bed 42 sq. feet, and a California king is 41.7 sq. feet.

What is the most cost-effective size mattress?

The most cost-effective mattress is one that you will get the most use out of over time. It is most important to think about all the considerations listed to choose the best mattress. The most popular mattress sold is a queen-size mattress. This size works well for most adults and even allows children to grow over time.

Is a California king the biggest mattress that I can get?

A California king is the largest standard-size mattress that you can buy. But there are several other non-standard sizes that are larger.

These include a Texas king which is 80” wide and 98” long, a Wyoming king which is 84” long and 84” wide, and an Alaska king that is 144” wide and 84” long.


The ideal mattress size varies from person to person. Mattresses are expensive and long-lasting purchases, so it is important to consider all the important factors before you purchase one.

The most important are who is sleeping in the bed, the size of the room, and your budget.

Your preferences will also impact this decision as this is a decision you will have to live with for years to come.