UK vs US mattress sizes: an easy guide

A woman stretching in bed
(Image credit: Getty Images)

Whether you drift off in Los Angeles or it's lights out in London, people in the US and UK look for similar things when choosing a bed: a comfortable sleep surface, decent pressure relief, and something that fits your bed frame. However, while sleepers around the world have a lot in common, bed size is not one of them. Confusingly, the UK and US use different mattress size standards.

It's worth making the effort to figure out dimensions, because buying the wrong size mattress is a nightmare. For a start, you sheets won't fit. More importantly, your mattress will either be too small for the bed frame, or worse – hanging over the edges. Even the best mattress can't support you if the ends are on the floor.

We've put together this guide to help you find the perfect mattress size, whatever side of the pond you lie on. We've also included some tips explaining which bed size is best for who, plus a quick look at European sizing (which is different again).

Are UK and US bed sizes the same?

US and UK bed sizes are different, both in terms of names and dimensions. These differences can be significant (we're talking several inches), so if you are buying from an international sleep brand, make sure you're choosing the right size for your bed frame. 

If you're not sure what size your bed frame is, the best thing to do is break out the tape measure and find out. In this guide, we've covered the measurements of the standard bed sizes in both the US and the UK, with both inches and centimeters to help you understand the sizing.

A couple lie on a bed smiling and cuddling each other

(Image credit: Getty Images)

And if you're worried about ending up with the wrong size, make sure to chose a bed with a long mattress trial. A mattress trial gives you several weeks (and sometimes an entire year), to test the bed and decide if it's right for you. That also means if you've accidentally ordered the wrong size, you can send it back without the hassle.

UK mattress sizes

The standard UK mattress sizes are single, small double, double, king, and super king. Each size is relatively self-explanatory – a single is for one person and a double is for two – but if you're trying to decide what size fits a space, it's best to know the dimensions.


  • Dimensions: 36 x 75 inches (90 x 190cm)

The smallest of the UK sizes, the single bed is for solo sleepers. It's also good for children and teenagers, as well as being a convenient size for a spare room. Its closest US equivalent is the twin, which is slightly wider.

Small double

  • Dimensions: 48 x 75 inches (120 x 190cm)

A small double is a good choice for anyone who sleeps alone but likes to stretch out. it can also accommodate two adults (although it's not quite as comfortable as a double or king). A small double is a good choice for a guest room. It sits between the twin and the full on the US mattress chart.


  • Dimensions: 54 x 75 inches (135 x 190cm)

Typically used by couples (or one person who likes their space) the double is one of the most common mattress sizes in the UK. The UK double is equivalent to the US full mattress size.

A man lying on a bed, asleep

(Image credit: Getty Images)


  • Dimensions: 60 x 79 inches (150 x 200cm)

Great for couples and families, there are many people who can benefit from a king size mattress. Confusingly, a UK king is similar to a US queen size – not the US king size.

Super king

  • Dimensions: 71 x 79 inches (180 x 200cm)

The biggest commonly available size in the UK range, the super king is for couples, families, and solo sleepers who like a lot of space. A UK super king has an equivalent width to the US California king and a similar length to a US king. 

US mattress sizes

The most common US mattress sizes are: twin, twin XL, full, queen, king, and California king. The twin sizes are best for solo sleepers, while full, queen, and king can all accommodate two people. US sizes tend to be slightly larger than their nearest UK equivalent.


  • Dimensions: 38 x 75 inches (97 x 190cm)

Excellent for solo sleepers and children, as well as useful for spare rooms, the twin is the smallest of the US mattress sizes. It's comparable to the UK single (but wider).

Twin XL

  • Dimensions: 38 x 80 inches (97 x 203cm)

Longer than the twin but with a similar width, the twin XL is particularly good for growing teenagers and solo sleeping adults, who don't want their toes sticking out the end of the bed. (The closest UK equivalent is the long single – this isn't the most common size, but some sleep brands do use it. For example, Tempur mattresses often comes in long single.)


  • Dimensions: 54 x 75 inches (135 x 190cm)

With room for two adults, the full is good for couples with limited floor space. It's also a great choice for adults who sleep alone, as it offers enough space to stretch, without dominating the room. It's equivalent to the UK queen.

A woman wearing a sleep mask lies in bed

(Image credit: Getty Images)


  • Dimensions: 60 x 80 inches (152 x 203cm)

One of the most popular mattress sizes in the US, the best queen mattresses are comfortable for couples. The US queen size is a close equivalent to the UK king.


  • Dimensions: 76 x 80 inches (193 x 203cm)

The best king mattresses are excellent for couples, especially those that might occasionally share with their kids (or pets). The US king is closest in size to the UK super king, but with greater width. King size is also often available as a split king. This has the same dimensions, but the mattress is split in two.

California king

  • Dimensions: 72 x 84 inches (183 x 213cm)

With plenty of length but still wider than a queen, the Cal King is ideal for taller couples. It has a similar width to the UK super king, but has more length. California king is also sometimes sold as a split bed – the split cal king.

What about European mattress sizes?

European mattress sizes are different to both UK and US sizes, although they're closest to standard UK sizing. However, those small differences will be noticeable if you're trying to put an EU mattress on a UK bed frame. Some UK sleep brands do sell beds in European sizes (Emma Sleep, for example) – double check you have the right size selected before adding to cart.

  • EU Single: 36 x 79 inches (90 x 200cm)
  • EU Double: 55 x 79 inches (140 x 200cm)
  • EU King: 63 inches x 79 inches (160 x 200cm) – see note
  • EU Grand King: 71 x 79 inches (180 x 200cm)

Slightly confusingly, EU king seems to sometimes also be known as the EU Queen – at least, that's what Emma Sleep calls this sizing.

Ruth Jones
Staff Writer

Ruth is TechRadar’s Sleep Writer. She’s here to help you find the perfect sleep setup for your budget and personal preferences. As well as keeping a keen eye on everything that’s going on in the world of mattresses, she regularly speaks to experts to help you learn how to improve your sleep habits, whether that’s by debunking sleep myths or explaining the science behind it all. Prior to joining the TechRadar team, she wrote features and product guides for new parents hoping to get a decent night's sleep, as well as writing for a variety of online spaces.