Full bed size: how big is a full sized bed?

Illustration showing mattress sizes
(Image credit: Future)

A 'full' mattress is not quite what it sounds like. Measuring 54 x 75 inches (191cm x 137cm), it's actually in the middle of the size spectrum in terms of US mattress sizes: larger than a twin but smaller than a queen. And that can make it the best mattress for both singles and couples, for quite different reasons. 

For singles, especially children and teens, a full mattress offers more space to spread out in than a twin size bed. For couples meanwhile, a full mattress takes up less room than a queen size bed or king, making it a good space-saver in a small apartment. They tend to be cheaper too, especially when they crop up in mattress sales, making them a popular 'transition mattress' for first-homers.

If you're looking for a new mattress, then, a full mattress, which is also known as a double size mattress, is well worth considering. In this article, we explain exactly how they compare to different sizes of mattress, and give you the information to decide whether a full mattress is right for you.

What are the dimensions of a full size bed?

A full size bed is 75 inches long and 54 inches wide (approximately 191cm long and 137cm wide). 

How big is a full size bed?

A full-size bed, aka double bed, is 54 inches wide and 75 inches long (approximately 137 x 191cm). That makes it smaller than a queen bed size (60 x 80 inches; approximately 152 x 203cm), and much smaller than a king bed size (76 x 80 inches; approximately 193 x 203cm). In other words, a full-sized bed is the smallest size that can hold a couple. 

Illustration showing all US mattress sizes

(Image credit: Future)

A full is a good choice for shorter/thinner people, who don't need the extra length of a queen or king, and will gain extra floor space as a result. Because of its smaller size, it's also good for small rooms, such as guest rooms and attic rooms. Plus it's likely to be cheaper than a queen or king mattress, making it a good option for young couples moving into their first home together. 

As well as couples, a full-size mattress is an option for single people who want more space in bed than a twin XL (38 x 80 inches / 97 x 203cm), such as older children and teens. Conversely, a full-size mattress is not the best option for couples with a healthy budget, a large bedroom and who want more space to spread out in, as well as to welcome pets and children into bed; a queen or king will serve these needs better.

The other thing to take into account is that many mattresses simply don't come in a full size, starting instead at queen and working up, or simply missing out the full size altogether. That said, you won't have to look too hard to find one. 

Full vs queen size bed dimensions

There's a big difference in size between a full mattress and a US queen mattress. A full mattress measures 54 x 75 inches (137 x 191cm), while a queen mattress measures 60 x 80 inches (152 x 203cm), making it both wider and longer. 

A full mattress is a good choice for couples with smaller bedrooms, as it will give you greater floor space. A full mattress is often cheaper than a queen, too, making it an affordable choice for first-homers. 

Furthermore, single sleepers including children and teens may like a full mattress for the extra space, but where a queen mattress would be overkill.

Conversely, couples with a larger bedroom may prefer a queen, as this will allow you more space to spread out in bed, especially if you like to invite pets or kids to join you on the mattress. 

Double bed vs full size

A full mattress is 54 inches wide and 75 inches long (approximately 137cm wide and 191cm long). It's also often referred to as a double mattress. To be clear, in the US, a full mattress and a double mattress are the same thing.

On the other side of the Atlantic, no one uses the term 'full' but a UK double is almost the same size. It measures 135 x 190cm, which is approximately 53 x 75 inches; so there's less than an inch difference in both length and width between a UK double and a full/double in the US.  

The next size up from a UK double is a UK king, which is 150cm x 200cm (approximately 60 x 79 inches). The next size down is a small double, which (to confuse matters further) is also referred to as a UK queen, despite being considerably smaller than a US queen. This measures 120 x 190cm (approximately 48 x 75 inches). 

There is no direct equivalent to the full/double size in the EU. The closest size is the Euro double, which measures 140 x 200cm (approximately 55 x 78 inches).

UK double and US full mattress size

(Image credit: Future)

Twin vs full size bed dimensions

A full mattress is 54 inches wide and 75 inches long (approximately 137cm wide and 191cm long). A twin mattress is 38 inches wide and 75 inches long (approximately 97cm wide and 191cm long). In other words, a full mattress is the same length as a twin, but 16 inches (approximately 40cm) narrower. 

A twin mattress is only suitable for single sleepers, and is a good choice for children, teenagers, bunk beds, small bedrooms, and guest rooms. A full mattress, meanwhile, is suitable for couples, as well as single sleepers who want more space in bed. 

A Twin XL is 38 inches wide and 80 inches long (approximately 97cm wide and 203cm long). In other words, it's the same width as a twin, but five inches (approximately 12cm) longer. Compared with a full mattress, a twin XL is 16 inches (approximately 40cm) narrower but five inches (approximately 12cm) longer. 

In this light, a twin XL mattress is a good choice for tall people who want a single bed with more legroom. In comparison, a full mattress would provide more width, but five inches less length to stretch out in. Plus a Twin XL mattress takes up less room overall, so is a good choice for smaller rooms such as guest rooms.

Tom May

Tom regularly writes about sleep for Tom's Guide and our sister site T3.com. Over the years he's tested a number of mattresses, duvets and pillows, and as a back pain sufferer, has a keen interest in finding ones that offer maximum support. Plus, in running a successful Airbnb business, sleep hygiene and providing the right bedding for guests has become a big part of his day-to-day life.