UK bed sizes: bed and mattress size guide

You might think there are only three adult mattress sizes – single, double and king – but adult mattresses actually come in 10 different sizes. Find out what they are and discover the most popular mattress size with Which? members. 

All these mattress size options should make it easier to buy a mattress that's just right for you, but it also increases the risk of buying one only to find it doesn’t quite fit your bedframe or sheets.

A bigger size may help you sleep, but getting a mattress that provides excellent long-lasting support for your body size and sleeping position will help even more. 

Find the best mattress for you budget with our guide to the best mattresses.

UK mattress sizes

This table shows the full range and dimensions of adult mattresses available to buy in the UK.

See all the mattresses we've tested and compare mattresses using our mattress reviews.

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How big is a single mattress?

Small single mattresses

A small single mattress measures 75 x 190cm (approximately 2ft 6in x 6ft 3in).

• Also known as a narrow single mattress, this is the smallest adult bed you can buy. 
• While it’s the same length as a standard single – and therefore long enough for most adults – it’s 15cm narrower.
• Small single mattresses are often used fo​​​​r children, but they’re also a good option for a box room or study that you want to use as a small guest bedroom.

Standard single mattresses

A standard single mattress measures 90 x 190cm (approximately 3ft x 6ft 3in).

• Unless you’re a lot taller or broader than average, this is the right size for a single adult.
• This should be enough space for the average adult to roll into a different sleeping position during the night.

Euro single mattresses

A European single mattress measures 90 x 200cm (approximately 3ft x 6ft 6in), making it 10cm (3in) longer than a standard single.

• If you’re looking for a single mattress but find that your feet tend to dangle over the edge of the bed, you might want to consider a European single mattress.

How big is a double mattress?

Small double mattress (queen-size)

A small double, or queen-size, mattress measures 120 x 190cm (approximately 4ft x 6ft 3in).

• This is the same length as a standard double but 15cm (6in) narrower, which is why it’s also known as a small double mattress.
• Two adults will find a small double mattress pretty snug, but it could be just the thing for a small bedroom or if you sleep alone but like room to stretch out.

Standard double mattress

A double mattress measures 135 x 190cm (approximately 4ft 6in x 6ft 3in). It’s the second most popular mattress size.

• This size tends to look well proportioned in most bedrooms, and it’s the mattress size we use in our tests.
• It's generally long and wide enough to accommodate two average-sized adults, but there might not be much wiggle room. Ideally, you and your partner should both be able to lie on your back with your hands behind your head without your elbows touching each other or the edge of the bed.

Euro double mattress

A European double mattress measures 140 x 200cm (approximately 4ft 9in x 6ft 6in).

• You might consider this size if a standard double feels a tad too cosy but your bedroom isn’t quite big enough for a king.
• It’s less widely available than a standard double, so you might need to shop around. International manufacturers, such as Ikea, tend to stock it, but it’s less common at high street retailers.

What size is a king-size mattress?

King-size mattress

A king-size mattress measures 150 x 200cm (approximately 5ft 3in x 6ft 6in).

• Nearly half of Which? members own a king-size mattress, making it the most popular size – and they're widely available. 
• While a king-size can be a fair bit more expensive than a double, it will provide a lot more sleeping space.

Euro king-size mattress

A European king-size mattress measures 160 x 200cm (approximately 6ft x 6ft 6in).

• As with the European versions of the single and doubles, the Euro king-size mattress is a fraction bigger than a standard king-size. 
• The length is the same, but it’s 10cm (3in) wider, giving you a touch more space to roll over and switch sleeping positions during the night.

Super-king mattress

A super-king mattress measures 180 x 200cm (approximately 6ft x 6ft 6in).

• A super-king mattress is the size of two standard single mattresses side by side. In fact, some super-king mattresses are literally just that, with a growing number of couples opting for two different singles that zip together to form a super-king. This means each person can get the firmness that suits them.

Emperor-size mattresses

An emperor-size mattress measures 200 x 200cm (approximately 6ft 6in x 6ft 6in).

• An emperor mattress is the biggest you can get, easily big enough for two larger-than-average adults and basically an enormous square.
• Not many brands make mattresses this big, so you might need to shop around and be prepared to spend significantly more.

Shopping for a new mattress? We round up the best mattress deals every month.

Are Ikea mattress sizes different to standard UK mattresses?

Confused by Ikea mattress sizes? You’re not alone, as Ikea sells both double and Euro double mattresses.

If you bought a bed from Ikea some time ago, you might have a European double, so before you buy a new mattress, it’s worth checking what size Ikea bed you have. The mattresses are sometimes listed separately on the Ikea website, so try searching by mattress name and check you’ve chosen the correct size for your bed.

On some mattress pages on the Ikea website, there’s a ‘choose size’ box, so make sure you select the correct size here before buying.

All the Ikea mattresses we test are standard UK double mattress size (135 x 190cm), although the thickness can vary.

See our Ikea mattress reviews.

How to choose the best bed size for your bedroom

No matter how much you like the idea of stretching out on a huge new emperor mattress, you need to consider how the bed will look in your bedroom. A huge bed in a small bedroom can look out of place, as can a small bed in a huge room.

A ratio of around 1:3 between bed and bedroom is sometimes said to look best, but that can be difficult in practice. Following this advice would mean, for instance, that for a king-size bed (150 x 200cm) you'd need a 6 x 8-metre bedroom. 

At the very least, you should aim for a space of 2ft 6in (76cm) between the sides and bottom of the bed and your nearest wall or piece of furniture.

And don't forget to check where you plug sockets are, so you don't inadvertently block access with a bed that's too big.

Looking for a new bed? See our guide to how to buy the best bed.

Bed, sheet and duvet sizes

Once you've got your new mattress, you'll need bedlinen to fit it.

The following measurements should help you choose the right sizes for your mattress.

Sheet and duvet sizes can very by brand, so always double check dimensions.

We rate the top duvet brands in our guide to the best duvets.