Mattress Sizes and Dimensions Guide

Whether you’re remodeling the bedroom or upgrading your mattress, it’s helpful to determine the best mattress size for your space. The number of options in today’s market can be overwhelming. What’s the difference between a full and a queen? How big is a California king? This comprehensive mattress dimension guide answers all of those questions and more.

Once you’ve learned a little about today’s mattress sizes, we’ll help you choose the best mattress for your home and lifestyle.

Mattress Dimensions Guide

Standard mattress sizes, dimensions, and names vary from country to country. Two mattresses of the same size may even have slight variations by manufacturer. If you live in the U.S., these mattress dimensions are considered standard across brands. In general, standard mattress depths range from about 9-13 inches when the high contour is considered.

Remember, widths can vary between the U.K. and the United States, so check the dimensions before you order those fancy European sheets online. According to the International Sleep Products Association, most beds are 74 or 80 inches long in the U.S. Meanwhile, the length is typically 75 or 78 inches in the U.K. It seems minimal but makes a big difference when considering the fit of a frame and sheets.

Below, find the standard mattress dimensions for the U.S. and Canada along with helpful information and common misconceptions about these mattress sizes. We’ve also included a handy room guide to know what size bed your room can accommodate.

Mattress Size Chart

Mattress SizeDimensions in InchesDimensions in Centimeters
Twin38 inches by 75 inches96.5 cm by 190.5 cm
Twin XL38 inches by 80 inches96.5 cm by 203.2 cm
Full53 inches by 75 inches134.6 cm by 190.5 cm
Full XL53 inches by 80 inches134.6 cm by 203.2 cm
Queen60 inches by 80 inches152.4 cm by 203.2 cm
King76 inches by 80 inches193.04 cm by 203.2 cm
California King 72 inches by 84 inches182.8 cm by 213.3 cm

Quick Room-Size Guide

Below, we’ve listed the standard mattress sizes and the minimum bedroom size needed to fit each bed.

Mattress SizeRecommended Room Size (feet)Recommended Room Size (cm)
Twin7 foot by 10 foot213.3 cm by 304.8 cm
Full9 foot by 10 foot 274.32 cm by 304.8 cm
Queen10 foot by 10 foot 304.8 cm by 304.8 cm
King10 foot by 12 foot 304.8 cm by 365.7 cm

Full Size Crib Mattress

Since safety is a top priority for cribs, the size of cribs and mattresses is regulated by the federal government. A full size crib mattress must be at least 27 1/4 inches wide and 51 1/4 inches long. The mattress cannot be more than 6 inches thick.

Room Size

A crib, of course, won’t take up much room. But it’s important to keep in mind most building codes require a bedroom to measure at least 70 square feet, like a 7-by-10-foot room. The ceiling height must also reach 7 feet, 6 inches.

You can certainly create a cozy nursery in an attic room or something comparable to fit a crib and a comfy chair. However, these smaller rooms won’t be considered bedrooms when it comes to a real estate listing. No matter what, make sure there is a planned fire escape route if you are squeezing things in tightly.

What Size Is a Twin Mattress?

Some people incorrectly think a single bed is smaller than a twin. The terms are actually interchangeable for the same sized mattress. Standard twin mattresses are 39 inches wide. Regular twin mattresses are 74 inches long, and a twin XL (extra long) mattress is 80 inches long.

Extra-long twin beds are commonly used in college dorm rooms. They’re ideal for taller people who may not be able to accommodate a wider mattress in their space.

Room Size

A twin size bed, and even a twin XL, can comfortably fit in a 7-by-10-foot room. It can also fit in a smaller room of about 6.5 by 6.5 feet but note this room will not be to code when it comes to real estate. It would also be quite cramped and only be able to fit a small wardrobe and desk.

If you need to fit two single or twin beds in one room, it needs to be at least 9 by 9.5 feet. This minimum size doesn’t offer much space between beds. Any added furniture, like desks or wardrobes, would need to be quite small.

If you have it, a 10 by 9.5-foot room or 10 by 10 room would fit two twin beds much more comfortably. Another way to fit two twins in a small space is to consider bunk beds. Kids’ bunk beds will need at least a 3-foot clearance, and they’re between 4 and 5 feet tall. The minimum ceiling height for kids’ bunk beds is about 7.5 feet.

For adult bunk beds, you’ll need a bit more clearance, and they run taller between 5 and 6 feet. Make sure your ceiling is at least 8 feet and 6 inches tall.

How Big Is a Full Size Mattress?

Double mattress dimensions and full mattress dimensions are the same, as the two terms are interchangeable. Full mattresses are 53 inches wide by 75 inches long. You can also get a double XL mattress measuring 53 inches wide by 80 inches long.

Room Size

The minimum room size for a full bed is 9 by 9.5 feet. This won’t leave much room for end tables, however. You might consider a headboard with built-in storage or an overhead bookshelf instead.

At 10 by 11 feet, you have a much more comfortable layout. In this case, you can fit wardrobes on the wall and have end tables flanking the bed. When determining your layout, make sure to accommodate clearance for the door to open and close fully.

Dimensions of a Queen Size Mattress

Many mistakenly think full and queen beds are the same size. In fact, a queen bed is larger. Queen mattresses are 60 inches wide by 80 inches long. It’s 7 inches wider and nearly 6 inches longer than a full size or double bed.

Room Size

To fit a queen size mattress, your room should measure at least 9.5 by 10 feet. Since a queen isn’t too much larger than a full, the dimensions are relatively similar. Remember, queen mattresses are about 7 inches longer. You might need to account for more space for things like closet door clearance. Sliding or pocket doors are a great way to fit a larger mattress into a small room since you don’t need to accommodate for the swing-out.

King Size Mattress Dimensions

A standard king mattress is 76 inches wide by 80 inches long. For your foundation, you can use two twin XL beds. A California king is 72 by 84 inches — it’s longer than a standard king, but not as wide. There’s also the less common Texas king or athletic king. This bed is 80 by 98 inches.

Room Size

Since a king is 16 inches wider than a queen, you’ll need a spacious room to accommodate one. The minimum bedroom size is 9.5 by 11.5 feet. However, if you move up to 12 by 12 feet, you’ll have a much more comfortable layout. This way, you’d have room for end tables and a wall of wardrobes.

At 13 by 12 feet, you can squeeze in a California king. Queen- and double size beds would fit in these rooms as well. With a smaller bed, you would be able to add furniture and decor like a standing mirror, desk, or vanity.

Antique Beds and Irregular Mattress Sizes

If your home is filled with antiques and vintage finds, you may want an antique bed to fit your decor. The next challenge is to source an appropriate mattress.

Many antique beds were about three-quarters of the width of today’s full sized mattress. These smaller beds are often called three-quarter beds for this reason today. They are about 48 inches wide compared to 54 inches for today’s double mattress.

Many vintage beds are the same length as today’s full mattress at 75 inches. That said, variations based on time period and maker are common. Older antique beds might be much shorter.

Other irregular bed sizes include a Texas or athletic king (70 by 82 inches), California queen waterbed (60 by 84 inches), and California king waterbed (72 by 84 inches).

Thankfully, there are many mattress companies that specialize in custom orders for irregular or antique beds. Measure the interior of your bed frame, then call mattress companies for their quotes. You can also convert your vintage bed to work with a full mattress, but only attempt this if you are handy and have some time and guidance.

How to Choose a Mattress Size

There are several factors to determining the best bed size for you. The first is practical — your room size. You’ll need to make sure your bed will actually fit in the space. Measure the width of each wall, and consider the other furniture you’ll need to accommodate. If you are happy with a long and short side of the bed against the walls, you can fit a larger mattress.

Many people prefer to have space on either side of the bed, as it’s generally considered more aesthetically appealing. Measure any nightstands you plan to place there, and leave enough space to fit them comfortably on either side of the bed. Don’t forget your door will take up space as it swings open.

Once you’ve determined what will fit into your room, think about your lifestyle. Single sleepers might be happy with a double bed or even a twin. If multiple children sleep in one room, consider bunk beds.

For those who share a mattress, you’ll want a double or queen size bed. If you have space, you might sleep more comfortably in a king bed. Think about how luxurious it is to spend the night in a roomy hotel bed. If you’re tall, you might want the extra length and legroom of a California king size.

The last aspect to consider is your budget. Larger mattresses cost more. A king size mattress is more expensive than a queen or a double, and a California king is even pricier. Perhaps you spend more on your main sleeping space and save on a smaller mattress in your guest room.


What is the most popular bed size?

According to Statista, 47% of adults age 18 and up sleep on a queen size bed. King is second-most popular at 19%.

What is the largest mattress size available?

A California king is the largest standard mattress size at 72 by 84 inches. Although less common, a Texas king or athletic king is also available at 80 by 98 inches.

Can you use a queen size mattress on a double frame?

No, you want to make sure your frame and mattress size match. If you are trying to use an antique bed frame with a modern mattress, however, it is usually possible to modify the frame. Unless you’re particularly handy, we suggest taking this task to a professional.

Can I push two twin beds together?

Two twin beds pushed together are a little smaller than a king. So if you buy king size sheets, they won’t fit ideally. Two twin XL beds, however, are equal to a king. Don’t try to push two twin bed frames together for a king mattress — the frame will be too short.

How high should a mattress be?

Mattress thickness can vary by material. In general, mattresses should be a foot high, give or take. Innerspring mattresses will typically be thicker than memory foam. When shopping for memory foam mattresses, density is as important as height. Extremely dense foams, at about 8 pounds, can be hard to move around on. On the other end, if the density is too low, less than 3 pounds, the mattress will quickly deteriorate.

Rest Easy With a New Mattress

Knowing popular mattress sizes can put standard dimensions into context. Once you have an idea of what your sleeping space can accommodate, think about the best mattress for your lifestyle.

A single person may want to save money and choose a smaller bed. Meanwhile, those sharing a mattress might prefer the extra space afforded by a queen or king. Tall people may need an extra-long bed.

Consider your lifestyle and budget before researching mattresses on the market. Sweet dreams.

Medical Disclaimer: The information contained on the site should not be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for informational purposes only.

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