What are the Differences in Mattress Sizes?

Intuitively, the different sizes of beds seem easy enough to understand, right? The truth is, choosing the right size of your mattress can be more complicated than you may think. Does it fit nicely in my bedroom? Is there enough leg room? So many questions come to mind.

To help you make the best decisions when selecting a mattress, we’ve put together a summary of the most common measurements you will see online and in stores so you can have an idea if it’s a perfect bed for you and your bedroom.


Dimensions: 27″ X 52″

These crib mattress size dimensions are widely accepted to be the standard across the U.S., so this bed size will fit any standard crib. For safety reasons, crib mattresses are firmer than adult mattresses and most commonly foam or innerspring mattresses.

A crib mattress is the right bed size for your baby’s first bed and will fit most babies until toddlerhood.


Dimensions: 39″ X 75″

Twin mattresses, also known as single mattresses, are slim in size, which makes them easy to fit side by side in shared kids bedrooms or stacked as bunk beds. Twin beds are the size most kids sleep on through childhood and are easy to move around.

Best for solo sleepers from toddlers and teens to adults who are shorter than six feet.

Twin XL

Dimensions: Approximately 39″ X 80″

As the standard bed size for college dorm rooms, a twin XL mattress gives students room to stretch out but doesn’t offer any more width than a conventional twin-size mattress. Although this mattress is easy to move around, adults prefer a larger bed size once circumstances allow.

Best for taller kids and students living in college dorms.


Dimensions: Approximately 54″ X 75″

Full-size mattresses provide a good compromise between twin and queen-size mattresses. A full bed size offers a good amount of space for single sleepers and is a good bed size option for a guest bedroom.

A good option for teens who have outgrown their childhood beds and individuals who have smaller apartments looking for an economical price and size.


Dimensions: Approximately 60″ X 80″

Queen bed size dimensions are the most popular because they are perhaps the most versatile bed size. Queen mattresses give sleepers enough space to sleep comfortably while still fitting in smaller bedrooms.

Best for adult couples or single sleepers who are looking for a mattress size they won’t outgrow but that is not as tall or wide as a king bed.


Dimensions: Approximately 76” X 80”

Offering a luxurious amount of space, king mattress sizes give couples the equivalent of a twin XL mattress size to themselves. King-size beds sit atop two twin box springs pushed together to make maneuvering an entire king bed into a room much easier. King-size mattresses are wider but shorter than California king-size mattresses.

Best for couples or single sleepers who don’t want to compromise on sleeping area, especially if they share bed with large pets or young children and find a queen-size mattress lacking in space. Most master bedrooms can accommodate a king-size bed.

California King

Dimensions: Approximately 72” X 84”

California king-size mattresses take approximately four inches of width from a conventional king-size bed and add it to their overall length. If your feet have always hung off the edge of a mattress, a California King bed will provide you with the length you need while still having more width than a queen-size bed.

Best for taller sleepers, especially those over six feet, who need a longer mattress to sleep comfortably. With slightly narrower dimensions, a California King mattress size is best for certain rooms where a wider king-size mattress may not fit.

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