Article updated on December 22, 2023 at 7:00 AM PST

Mattress Sizes: The Ultimate Guide to Choosing the Best Bed Size for You

Trying to decide which mattress size is best for your bedroom? Is a California King mattress too big? Here's everything you need to know about bed sizes and dimensions.

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McKenzie Dillon
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McKenzie Dillon Writer
McKenzie, a Certified Sleep Science Coach and proclaimed mattress expert, has been writing sleep content in the wellness space for over four years. After earning her certification from the Spencer Institute and dedicating hundreds of hours to sleep research, she has extensive knowledge on the topic and how to improve your quality of rest. Having more experience with lying on mattresses than most, McKenzie has reviewed over 150 beds and a variety of different sleep products including pillows, mattress toppers and sheets. McKenzie has also been a guest on multiple radio shows including WGN Chicago as a sleep expert and contributed sleep advice to over 50 different websites.
Expertise Certified Sleep Science Coach, Certified Stress Management Coach, Bachelor of English.
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When you shopping for a mattress, there are many factors to consider, including firmness, material and feel. Mattress size is another important factor many people think less about, but it's actually one of the most important aspects. More than just the dimensions of the mattress, size helps determine how much you will spend on your mattress. 

You have your pick between a range of mattress sizes, from a single-person twin-sized bed (for when your kid is too big for a crib) to an extra-wide California king fit (for couples who like to sprawl). The mattress size you choose will depend on your height, weight and preferences. In this mattress sizing guide, we explore the dimensions of each bed size, from the most common to custom-made options. 

Standard mattress sizes 


38 by 75 inches (96.5 by 190.5 centimeters)

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A twin size is best for children, or single sleepers who want to maximize the space in their room. Because they take up very little space, they can fit in room sizes as small as 7 by 9 feet. Twin-size mattresses are popular for kids because it's the least expensive size you can buy, and the bed won't take up as much space in their bedroom, leaving them room to play.

Read more: Best Twin Mattress

Twin XL

38 by 80 inches (96.5 by 203 cm)

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Twin XL is a long twin mattress and is best for taller children, young adults in college, or single-sleeping adults who need extra legroom. An 8- by 10-foot room is the smallest you should go to fit a twin XL mattress comfortably. It's also common for brands to have two twin XL mattresses as a split king. Keep in mind that it's harder to find bedding to fit a twin XL mattress because the size is most commonly used in college dorms. That means you can usually find plenty of twin XL bedding during back-to-school season. Outside of that, you might be limited in what you can buy.


53 by 75 inches (134.5 by 190.5 cm)

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Because full-size mattresses are bigger than a twin but cheaper than a queen, they're popular for young adults or couples who don't mind cuddling to maximize the space in their bedroom. The recommended room size for a full-size mattress is at least 10 by 10 feet. 

Read more: Best Full Mattresses


60 by 80 inches (152.5 by 203 cm)

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Queen-size mattresses are best for single sleepers who enjoy their space. They're also good for couples, just as long as nobody is over 6 feet and 5 inches. It's currently the most popular mattress size in North America. The recommended room size for a queen-size mattress is at least 10 by 11 feet. 

Read more: Best Queen Mattresses


76 by 80 inches (193 by 203 cm)

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A common choice for couples with kids or single-sleepers who like extra space to spread out, the recommended room size for a king mattress is at least 12 by 12 feet. A larger size bed comes at a higher cost, both for the mattress and the bedding, so keep that in mind if you are on a budget.

Read more: Best King Mattresses

California king 

72 by 84 inches (183 by 213 cm)

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A California king is longer than a standard king, but not quite as wide. It's best for tall single-sleepers or couples who have pets who sleep on the bottom of your mattress. 

Read moreBest California King Mattress

Other mattress sizes

Maybe the mattress sizes listed above don't suit what you're looking for. Instead, you want something that fits between that one random nook in your bedroom, or an extra-oversized mattress so your big family can join together for movie nights. Here are the less common mattress sizes that are also available with some mattress companies.  

Olympic queen

66 by 80 inches

An Olympic queen mattress is slightly wider than a normal queen mattress. That extra six inches of space can be helpful for those who sleep with a partner or a pet. Keep in mind that most queen sheets might not fit an Olympic queen bed. Look for oversized bedding. 

Full XL

54 by 80 inches

A good compromise between a full and a queen size is a full XL. It offers the same width as a full mattress but is just as long as a queen. Single-sleeping adults who need the extra leg and or pet space typically would be well-off on a full XL bed. Keep in mind, it will be a little harder to find bedding for a full XL mattress than a full or queen. 

Crib size

27.25 by 51 inches 

Crib mattresses are made specifically for your baby's crib. These mattresses are about 6 feet by 4 feet and are firm (the firmer, the better) to fully support a baby's body from sinking too far into the bed. When shopping for a crib mattress, you can choose between a foam and an innerspring bed. 

Read more: Best Crib Mattress

How to choose a mattress size

Selecting the right mattress size is essential for a good night's rest. Keep these things in mind when shopping for a new mattress.

  • Room size: Be sure to measure your room to determine how much space you have for a mattress and bed frame.
  • Number of sleepers: Are you sleeping alone? Or are you sleeping with a partner and three kids? If it's just for you, a twin or twin XL mattress may suffice in a small room. For couples, a queen or king mattress is suitable.
  • Comfort and sleeping position: Believe it or not, your sleeping position plays a role in choosing the right mattress size. Back and stomach sleepers can usually make any mattress size work. For side sleepers, a queen or king mattress allows for more space to stretch out comfortably.
  • Budget: No surprise here. The bigger the mattress, the bigger the price tag. Consider your budget and balance it with your need for comfort.
  • Further needs: Your mattress is a large investment that can last you for years to come. Think about the near future and if your mattress can adjust to your plans. For example, if your family is likely to grow, you'd want to opt for a mattress that can suit children or pets.

While two people can fit in a full-size bed, you'll be more comfortable sharing a queen or king.

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Mattress size FAQs

Which bed size is best for a couple?

It depends on the space you have in your bedroom, and how much space you or your significant other require. For maximum space in your bedroom, a queen is perfectly suitable. Maybe even a full if you're down to cuddle. For large master bedrooms, king or California king beds would be ideal. 

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What's the most popular mattress size?

As of right now, the most popular mattress size is a queen which measures 60 by 80 inches. It offers ample space for single sleepers and couples and is more affordable than a king. 

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What's the difference between a king and a California king mattress?

A California king mattress measures 72 by 84 inches, making it 4 inches narrower and 4 inches longer than a king.

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Do two twin mattresses equal a King?

No. Twin beds are 5 inches shorter than a king. Two twin XL mattresses will make a king-size bed.

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