A Guide to Every Mattress Size—Plus, the Dimensions You Need to Choose the Right One for Your Space

We mapped out the six mattress sizes, including their length and width measurements, to help you select the best option for your bedroom.

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Photo: Katarzyna Bialasiewicz/ Getty Images

Whether you're a side or hot sleeper, someone with chronic back pain, or the type of person who dozes off as soon as they lay down, the process of finding a new mattress can be anything but dream-like. With the variety of mattress sizes (they range from twin up to a California king) on the market, predetermining the best one for you and your space can, well, keep you up at night.

To streamline your decision, we tapped Marissa Murphy-Adriaanse, the director of operations and e-commerce at Pioneer Linens, and the mattress experts at Avocado Green Mattress to share their tips and industry tricks.

There Are Six Mattress Sizes

Mattresses come in six different sizes: twin, twin XL, full (this is also often called double), queen, king, and California king. The size you select depends on your preferences, the number of people (pets included!) sleeping on it, and your bedroom's dimensions.


Experts at Avocado advise solo sleepers or small-space dwellers to opt for a twin mattress; they are ideal for apartment living, too, since they fit well into tighter rooms—and are easier to get up narrow staircases.

Twin XL

Don't confuse a twin mattress with a twin XL, which has the same 38-inch width, but is 5 inches longer. This extra length makes it better suited for tall solo sleepers, and is often found in dorm rooms.


The next size up is a full. "A full, also called a double, is ideal for individual sleepers [who prefer] more space or smaller couples who like to sleep close together," notes members of the Avocado team.


Continue up the size ladder and you'll land on the queen, which is the most popular mattress size, according to our experts. Per the Avocado team, this mattress size gives individual sleepers lots of space, and for most couples, the right balance of space and intimacy.


For those who have a sleep partner but love their personal space, a king-size mattress is ideal—if you have the room for it, that is. "A king-size mattress is perfect for couples who like to spread out, or for those who also sleep with a pet or child," says the Avocado team.

California King

Coming in 4 inches longer and slightly narrower is the California king. This iteration is best suited for taller couples who like their space and leg room.

The Dimensions of Every Mattress Size

Luckily, most mattress manufacturers adhere to these standard length and width dimensions, courtesy of the Sleep Foundation, which makes choosing the best iteration for your body's needs and your space a breeze.

Mattress Size Mattress Dimensions (width x length)
Twin 38" x 75"
Twin XL 38" x 80"
Full 54" x 75"
Queen 60" x 80"
King 76" x 80"
California King 72" x 84"

How to Measure Your Bedroom Before Choosing a Mattress Size

Regardless of your personal preference, it's most important to choose a mattress that will properly fit inside your bedroom. Before you shop, measure your room and compare the results to the dimensions provided above or by the mattress manufacture.

Establish a Minimum Clearance

Ideally, you need at least 2 feet of free space—3 feet is more comfortable—around both sides and the foot of the mattress; this clearance allows you to make your bed each morning with ease, eliminates visual cramping, and prevents doors and drawers from knocking into the bed frame and mattress edges when open.

Map Out Your Bedroom

For irregularly-shaped spaces or particularly tight areas, use painter's tape to map out the mattress' dimensions on your floor; then, measure the space between the edge of the bed and the wall to ensure the value is equal to or greater than 2 feet. Be sure to take your bed frame's numbers into account, too, since sizes aren't always standard. (Luckily, most bed frames take up little real estate, the Avocado team says, and some even offer nooks and drawers for extra storage.)

Consider Mattress Depth

After factoring in your room size, your ideal mattress size, and your bed frame's measurements, think about the depth of your mattress in relation to the rest of the room—and calculate the type (and size) of bedding you'll need to outfit your new haven. "In an ideal world, you want your mattress to be 14 inches deep," Murphy-Adriaanse says, noting that most sheet manufacturers create linens with this number in mind.

That means if you choose to splurge on a custom or non-standard size, it will likely cost you on all fronts. "If your mattress isn't 14 inches deep, then your fitted sheets will have to be custom-made to stay on your bed," Murphy-Adriaanse says, noting that standard width sizes are equally as important.

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