Single bed size: how big is a single bed?

single mattress size
(Image credit: Future)

If you're looking for the best mattress for your needs, one of the first things you need to think about is how big it should be. That will depend on a number of things, including who's going to be using it, how much space there'll be in the room it's going in, and how much you have to spend. 

Single mattresses are designed for one person, so they're no good for couples (unless you each prefer to sleep in your own single bed). For children, teens and single adults, though, they offer many benefits. These include low prices (especially if you bag a bargain in the mattress sales), more floor space in your bedroom, reducing your washing load, and being more environmentally friendly overall. 

In this article, we'll explain how big a single mattress is, and how it compares to other sizes in the UK, USA and EU. 

What are the dimensions of a single mattress?

A single bed is 75 inches long and 36 inches wide (that's 190cm long and 90cm wide).

How big is a single size bed?

A single bed is a UK size that's 75 inches long and 36 inches wide (approximately 190cm long and 90cm wide). It's a popular choice for children and teenagers, and is a standard size for bunk beds. It's also a potentially good option for single adults, as it's more environmentally friendly, is cheaper than larger sizes, saves money on bed linen and washing, and takes up less space. That makes it a particularly good choice for small rooms and guest rooms. 

Finally, some couples may prefer two single beds in the same room to one big bed, if one or other partner is a restless sleeper who disturbs the other in the night. That said, it's worth exploring other options first, such as having two duvets to prevent cover-stealing, finding a mattress with low motion transfer, or buying an adjustable bed.

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

You won't normally see a single and twin size mattress next to each other, whether you're shopping online or in a physical store, because a single is a UK size and a twin is a US size. 

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, both are about the same length, but the twin is a couple of inches wider.

A twin is the smallest of standard American sizes. The next step up in size is a twin XL, which is 38 inches wide and 80 inches long (approximately 97cm wide and 203cm long). That makes a twin XL the same width as a twin but longer by five inches. After that comes a US double, also known as full bed size, which is 54 inches wide and 75 inches long (approximately 137cm wide and 191cm long). That makes it the same length as a twin but 16 inches wider. 

The closest equivalent to a UK single in the European Union is the EU single, which is 90 x 200cm (36 x 78 inches). That makes an EU single the same width as a UK single, but longer by 10cm. 

UK single and US twin mattress size

(Image credit: Future)

Single vs double bed dimensions

A single is 90cm wide and 190cm long (approximately 36 inches wide and 75 inches long). A double mattress size is 135cm wide and 190cm long (approximately 53 inches wide and 75 inches long). In other words, a single is the same length as a double, but narrower by 45cm. In other words, it's two-thirds the width of a double.

A single mattress is designed for one person only, whereas a double is designed for two people. Note, though, that a double is not the largest size you can get for couples: a king size bed or super-king is larger.

Also, in practice many single sleepers, including older children, teenagers and adults, prefer a double to a single, as it gives them more room to stretch out in bed. The downside here is the extra cost, and the extra space the bed will take up in the room.

UK single and double mattress size

(Image credit: Future)

What is a small single bed size?

A small single is the smallest of the standard UK bed sizes. It's 75cm wide and 190cm long (approximately 30 inches wide and 75 inches long). In comparison, a single is 90cm wide and 190cm long (approximately 36 inches wide and 75 inches long). That makes a small single 15cm narrower than a single, but the same length. A small single is a good choice for very small rooms, where a single would take up too much space, and for small children, such as toddlers moving from a cot bed into their very first 'proper bed'.

What is a super single bed size?

A super single is a US bed size that's nowadays quite rare. It's 42 inches wide and 75 inches long (approximately 107 x 191cm) and sometimes referred to as a petite double. That makes it the same length but four inches wider than a twin, which is 38 inches wide and 75 inches long (approximately 97 x 191cm). 

You may find it difficult with a super single bed to source sheets that fit perfectly. In the last resort, you could always go for the next size up, which is a full, aka US double, which is the same length but 12 inches wider at 54 x 75 inches.

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Tom May

Tom regularly writes about sleep for Tom's Guide and our sister site 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.