Twin bed size: how big is a twin mattress?

twin mattress size — (Image credit: Future)

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Twin mattress size
XL twin vs twin size
Single vs twin
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When you're looking for the best mattress, it's important to take size into account. But don't be fooled: it's not always the case that the bigger, the better.

A twin is the smallest standard size for adults in the US, and comes with a number of advantages. It takes up less space in the room. It's cheaper to buy, especially if you take advantage of the latest mattress sales. It requires less bed linen and therefore less washing. And overall, it's more environmentally friendly than a large mattress.

So is a twin the right choice for you? In this article, we'll answer the most common questions about this mattress size, to help you make that decision.

What are the dimensions of a twin mattress?

A twin bed is is 38 inches wide and 75 inches long (approximately 97cm wide and 191cm long).

What are the dimensions of a twin XL mattress?

A twin XL bed is 38 inches wide and 80 inches long (approximately 97cm wide and 203cm long). Length is the primary difference between twin XL vs twin mattresses, so the longer twin XL is typically better for taller solo sleepers.

How big is a twin size bed?

A twin size bed is is 38 inches wide and 75 inches long (approximately 97cm wide and 191cm long). This size is only generally available in the US, and not in the UK.

Despite the name, a twin bed isn't really designed for two people. It's really only suitable for single sleepers, including children, teenagers and adults. That said, some couples prefer to sleep in separate beds, particularly if one partner is restless or disruptive during the night. In which case two twin beds, either pushed together or just in the same room, can be a good compromise.

Because of its size, a twin is a great choice for smaller rooms and guest rooms, and for anyone who wants to maximise floor space in general. Twin mattresses also tend to be cheaper than larger mattresses, and because they require less bed linen, will save you time, money and effort or washing too.

Despite these benefits, though, some people will prefer greater bed space overall, in which case a larger sized mattress will be more appropriate. The next size up in terms of length is the twin XL (38 x 80 inches, approximately 97cm x 203cm, which is better for taller people. The next size up in terms of width is a full mattress (54 x 75 inches, approximately 191cm x 137cm). And the next size up in terms of both is a queen mattress (60 x 80 inches, approximately 152 x 203cm).

XL twin vs twin bed: what's the difference?

A twin bed is 38 inches wide and 75 inches long (approximately 97cm wide and 191cm long). A twin XL bed, meanwhile, is 38 inches wide and 80 inches long (approximately 97cm wide and 203cm long).

That makes a twin XL five inches longer than a twin, but the same width. So a twin is best suited for single sleepers who are under six feet tall, while a twin XL is best suited for single sleepers who are 6 feet tall or taller.

It's also worth noting that a twin XL will take up more space, so a twin may be preferable for a small room or guest room. Also, a twin is generally cheaper than a twin XL.

Twin and Twin XL mattress size — (Image credit: Future)

Single vs twin bed size: what's the difference?

A single bed size is normally only found in the UK, while a twin bed size is normally only found in the USA. They're similar, but there is a difference.

A UK single is 90cm wide and 190cm long (approximately 36 inches wide and 75 inches long). A US twin is 38 inches wide and 75 inches long (approximately 97cm wide and 191cm long). In other words, a US twin is a couple of inches wider than a UK single, but both are approximately the same length.

A UK single is not the smallest of the standard UK bed sizes. That's a small single, which is 75cm wide and 190cm long (approximately 30 inches wide and 75 inches long). A small single is 15cm narrower than a single, but the same length. The next size up from a UK single is a UK double bed, which is 135cm wide and 190cm long (approximately 53 inches wide and 75 inches long). A double is the same length as a single, but 45cm wider.

The closest equivalent to a twin in the European Union is the EU single, which is 90 x 200cm (36 x 78 inches). That makes an EU single around three inches longer but two inches narrower than a US twin.

US twin and UK single mattress size — (Image credit: Future)

Twin vs full bed size: what's the difference?

A full mattress is 54 inches wide and 75 inches long (approximately 137cm wide and 191cm long). It's the smallest of the standard US sizes that will fit a couple. A twin mattress is 38 inches wide and 75 inches long (approximately 97cm wide and 191cm long). That makes it the same length as a full mattress, but 16 inches (approximately 40cm) wider.

For this reason, a twin is only suitable for single people. A full mattress, meanwhile, is suitable for couples, as well as single sleepers who want extra room. On the downside, a full mattress will cost more, and take up more space.

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Tom is a sleep product and mattress reviewer and reporter, who writes about everything from bed dimensions to how to wash and maintain key pieces of bedding such as mattress protectors and foam bed toppers. For Tom's Guide, he has produced a series of articles on the different mattress sizes and how to choose the right one for your bedroom space and sleep needs. Outside of Tom's Guide, Tom regularly writes about sleep our sister site T3. Over the years he's tested a number of mattresses, duvets and pillows, and as someone with back pain, 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.