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A Guide to UK Mattress Sizes

A Guide to UK Mattress Sizes

Elisa King |

When it comes to buying a mattress there are many things you have to consider; one of the most important being the size of the mattress. We realise that there’s a considerable amount of confusion about mattress sizing out there, so we’ve created a complete guide that tells you everything you need to know about UK mattress sizes. Keep reading to find out more!

What are the UK mattress sizes?

The UK uses a standardised set of mattress sizes. These standard sizes apply to both mattresses and bed bases - so if you buy a single sized mattress, it will fit a single sized bed base and so forth. Simple!

Like other forms of standardisation, the use of standardised measures makes the purchase of a bed easier. For example, if you want to buy a double sized bed base from one retailer, and a double sized mattress from a different retailer, you’ll know they’ll be compatible.

So, with that in mind, what are the standard UK mattress sizes? We’ve set them all out in the table below in metric and imperial measurements.

Mattress Size

Imperial Size (width x length)

Metric Size (width x length)

Small Single

2’6” x 6’3”

75 x 190cm


3’ x 6’3”

90 x 190cm

Small Double

4’ x 6’3”

120 x 190cm


4’6” x 6’3”

135 x 190cm


5’ x 6’6”

150 x 200cm

Super King

6’ x 6’6”

180 x 200cm

What size is a small single mattress?

Small single mattresses are ideal for children and petite adults. They are 75cm wide and 190cm long. Using imperial dimensions this is 2 feet 6 inches wide and 6 feet 3 inches long.

This size mattress is good for small rooms, or as a ‘transition’ bed for children who are moving from a cot to their first ‘proper’ bed.

What size is a single mattress?

For use by adults or children, small single mattresses provide a decent amount of room for a single sleeper. In metric units, a small single bed is 90cm wide by 190cm long. In imperial units, a single mattress is 3 feet wide and 6 feet 3 inches long.

A single mattress will often last an entire childhood - from toddler to adolescent.

What size is a small double mattress?

A small double mattress is 120cm wide and 190cm long. Using imperial measurements, a small double is 4 feet wide and 6 feet 3 inches long.

Because of their dimensions, small doubles are also known as ‘queen size’ mattresses or ‘three quarter’ mattresses. They provide plenty of space for a single sleeper, whilst two adults will ‘cosily’ fit on one.

Small double mattresses are commonly used in guest bedrooms where a full size double won’t be able to fit.

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What size is a double mattress?

One of the most popular sizes, a double mattress is 135cm wide and 190cm long. In imperial units, a double mattress is 4 feet 6 inches wide and 6 feet 3 inches long.

Two adults will be able to sleep comfortably on a double mattress, with sufficient room to move around.

What size is a king size mattress?

King size mattresses provide a large amount of space for two sleepers. With a king size mattress you should be able to sleep and change sleeping position without overly disturbing your partner.

A notable feature of king size mattresses is that they are longer than other mattresses at 6 feet, 6 inches in length (200cm). In metric units, a king size mattress is 150cm (5 feet) wide and 200cm long.

As you can imagine, king size mattresses (and beds) do take up a lot of room, so they should only be used in bedrooms with a large amount of floorspace.

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What size is a super king size mattress?

The largest of all UK mattress sizes, the super king mattress is 180cm wide and 200cm long. In imperial units that equates to 6 feet wide and 6 feet 6 inches long.

Super king size mattresses are perfect for couples who enjoy their own space. However, they’re also big enough if you want to spend a Sunday morning watching TV with the kids and pets on it too!

Again, like the king size mattress, a super king size mattress is only suitable for large bedrooms.

As you can see, there is a considerable difference between the smallest and largest mattress sizes. But, which one is right for you? That’s what we’ll cover in the following sections of this article.

What length mattress should I buy?

When it comes to the length of your mattress, you have two main choices, which generally correspond to the width of the mattress.

So, if you buy a single mattress it will be 6’3” (190cm) long. If you buy a king size mattress it will be 6’6” (200cm) long.

You want your mattress to be as supportive and comfortable as possible, so to buy the right length mattress for you, remember this:

You should buy a mattress which is at least 10cm longer than the tallest person who will be sleeping on it.

This ensures you don’t end up in a situation where you or your partner’s feet are dangling over the edge!

To help you select a mattress that fits your height, we’ve created a size guide below:


Mattress size

5’10” or shorter

Small Single, Single, Small Double or Double.

5’11” or taller

King or Super King.

6’3” or taller


Remember, these are only recommendations. Depending on the position you sleep in, you may not need a bed which is 10cm longer than your height.

Nevertheless, it’s worth bearing in mind the length of a mattress when buying one. Far too often, people only focus on the width of a mattress which can lead to an improper purchase decision.

What width mattress should I buy?

This is perhaps the most common question people ask when buying a mattress.

Sure, the standard advice is to buy the biggest mattress that will fit your bed/bedroom. But, we realise this advice isn’t exactly suitable for everyone’s circumstances.

To help you decide which width mattress is right for you, we’ve set out some things to think about below.

What is the most popular width mattress in the UK?

According to the National Bed Federation (the UK’s trade federation for bed manufacturers and retailers), the most common width mattress in the UK is a double.

A standard double is 4’6” which means that if each person shares the bed equally, they’ll only have 2’3” of space to sleep on. To put this into perspective, that’s proportionally less room than a baby has in a cot!

Sleeping as a couple in a standard double means that you’ll be very close together. Whilst some people like this, it does also mean that you’re highly likely to disturb your partner if you change sleeping position during the night.

Figure out how much space you each need

With one of the biggest causes of poor sleep being partner disturbance, the most important thing you need to do is figure out how much space you both need.

Rather than looking at the bed as a single entity, it’s best to divide it into two (see illustration below). Figure out which of you takes up the most room and measure what percentage of the bed they take up - you can do this using your old mattress as a guide.

Bed width guide

Once you’ve done that, and in conjunction with the measurement tables above, you can work out exactly what size mattress will work best for you.

Try a single mattress or zip and link bed base

If you have found that no matter what size mattress you buy, your sleep is still disturbed, then you could try purchasing two single beds or a zip and link bed base.

Don’t worry if you think doing this is unusual. The number of couples sleeping in separate single beds is on the rise. According to the Sleep Council’s Great British Bedtime Report 12% of couples said they slept apart, whilst a quarter of all couples said they slept apart at least some of the time.

So, if you’re keen to get a sound night’s sleep, consider trying one of our zip and link bed bases such as the one below:

Zip and link bed base together

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The bed base consists of two sections which are easily pushed together. They are then held in place using a linking bar. This linking bar is easily unhitched, meaning you can push the bases apart to create two separate beds:

Zip and link bed base apart

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If you want the option to be able to sleep alone, without resorting to the sofa, then consider a zip and link bed base.

Note - at Divan Base Direct our standard mattresses do not have zips to link them together. However we can make any of our mattresses into zip and link for a small additional cost. Please contact us for further details and prices.

How will you get your mattress into your bedroom?

This is something that catches the occasional mattress buyer out.

You definitely need to measure your bedroom to make sure you have sufficient space for your choice of bed/mattress, but it’s important to measure the route your mattress has to take to reach the bedroom as well.

Fail to do this and you may find that your chosen mattress doesn’t fit through your front door or up your staircase.

How to make sure your mattress fits your bed

As we have seen, mattress sizes are designed to correspond to bed sizes. So, a single mattress will fit a single bed.

However, there are a few nuances between the different types of bed. It helps to be aware of these when buying a new mattress:

  • Divan bed base - divan bed bases are designed to have the same dimensions as your mattress. So a mattress of the corresponding size will sit flush with the bed base (i.e. there should be no lips or overhangs between the bed base and the mattress).

  • Wooden bed frames - wooden bed frames are typically a few centimetres bigger than the corresponding mattress size. The mattress will sit on the bed, but the wooden bed frame will protrude slightly around the base of the mattress.

  • Upholstered bed frames - these can vary hugely depending on their shape, the amount of detail and the fabric they use. Make sure you get accurate measurements of this type of base before purchase.

You should always double check the dimensions of your bed base against the dimensions of the mattress you are buying.

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Do all of those things listed above and you’ll be able to buy the size mattress that’ll give you (and your partner), the best possible night’s sleep.

However, we’d like to finish with a final thought.

Although a particular size mattress may seem to be the right ‘fit’ e.g. you’re single and a single mattress will fit you, it’s generally better to buy the biggest mattress you can.

Your sleep is important. So, below, we’ve made the case for buying the biggest mattress you can.

Why you should buy the biggest mattress you can

Here are our top reasons why you should buy the biggest mattress you can:

  • You spend a third of your life in bed! If you’re going to be spending that long somewhere, you’ll want it to be as comfortable and spacious as possible.

  • It works out cheaper than you think to move up a mattress size. Over five years, the extra £100 you spend on a mattress works out at only 5.4p per night!

  • Larger beds are becoming the norm. Don’t be left behind! According to market research by GfK, 33% of divan bed sales are now king size or larger.

  • The average person changes sleeping positions between 60 and 70 times per night. If you want to get a good night’s sleep, make sure you’ve got plenty of room between you and your partner!

  • Once you’ve slept in a larger bed, you won’t want to go back to a smaller one!

Buy Britain’s best mattresses at Divan Base Direct

Whether you want to buy the largest mattress you can, or you’ve got a specific size in mind, you’ll find the best mattresses here at Divan Base Direct.

We not only stock all of the main UK mattress sizes, but we also have all main types of mattress including pocket sprung, memory foam, memory foam sprung mattresses, latex and orthopaedic mattresses.

Many of our mattresses come with an impressive 5-year warranty (see individual mattresses for more detail) and are available with free 2-man delivery.

Shop mattresses at Divan Base Direct now

For more mattress, bed base and headboard buying advice, explore the rest of the Divan Base Direct blog

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