Standard UK mattress sizes
Before we even begin helping you decide what size mattress you need, let's start off with a quick overview of what mattress sizes are available.
Different countries have different mattress sizes. π³
Here is an overview of the standard UK mattress sizes, looking at bed sizes in cm and inches:
Metric dimensions W x L (cm) | Imperial dimensions W x L (feet) | |
Cot | 60 x 120 | 1'9" x 3'9" |
Toddler | 70 x 140 | 2'3" x 4'6" |
Small single | 75 x 190 | 2'6" x 6'3" |
Single | 90 x 190 | 3'0" x 6'3" |
Small double | 120 x 190 | 4'0" x 6'3" |
Double | 135 x 190 | 4'6" x 6'3" |
King | 150 x 200 | 5'0" x 6'6" |
Super king | 180 x 200 | 6'0" x 6'6" |
Emperor | 200 x 200 | 6'6" x 6'6" |
Most UK retailers will only stock UK mattress sizes, though some brands will also have European mattress size options available.
Simba Sleep, for example, sells its acclaimed Simba Hybrid mattress in a variety of UK sizes but also offers European single, European double, and European queen size options.
IKEA mattresses are also more readily available in Euro sizes.
Let's take a closer look at the different UK mattress sizes.
UK cot mattresses
The standard UK cot mattress has dimensions of 60 x 120 cm (1'9" x 3'9").
Cot mattress | |
Dimensions (W x L): | 60 x 120 cm (1'9" x 3'9") |
Best suited to: | Cot bed frames, babies under the age of 2 |
These mattresses have been exclusively designed to fit cot beds and are meant for use by babies under the age of 2. πΆ
We're big fans of more natural cot mattresses, like the Little Green Sheep Natural Twist mattress.
We don't cover cot mattresses at length in this article but feel free to head over to our guide on cot mattresses and beds for more information.
UK toddler mattresses
The standard UK toddler mattress has dimensions of 70 x 140 cm (2'3" x 4'6").
Toddler mattress | |
Dimensions (W x L): | 70 x 140 cm (2'3" x 4'6") |
Best suited to: | Toddlers and small children aged 2 - 6 |
Toddler mattresses are one size up from cot mattresses. π§
They are intended to be used by toddlers and small children between the ages of 2 and 6.
Some mattresses, like the Mamas & Papas Premium Pocket Spring mattress, have dual sides for use by both babies and toddlers.
After age 6, most children are able to move on to adult small single or single-sized mattresses. π
UK small single mattresses
The standard UK small single mattress has dimensions of 75 x 190 cm (2'6" x 6'3").
Small single mattress | |
Dimensions (W x L): | 75 x 190 cm (2'6" x 6'3") |
Best suited to: | Children, narrow bed frames, guest beds |
Small single beds have been designed to fit narrower kids' bed frames. π
They're also a great save-spacing option for spare rooms, though this isn't the most comfortable size for adults.
UK single mattresses
The standard UK single mattress has dimensions of 90 x 190 cm (3β x 6β3β).
Single mattress | |
Dimensions (W x L): | 90 x 190 cm (3β x 6β3β) |
Best suited to: | Children, teenagers, young adults, small bedrooms |
This is a common size in children's bedrooms, but it also works well for teenagers, students, or in very small bedrooms. π©βπ
You'll find this as one of the most common student mattress sizes - some universities actually insist on single beds as the standard student mattress size to discourage overnight guests!
We wouldn't recommend a standard single mattress size UK as a long-term comfort choice for adults.
That said, many couples choose to combine two single mattresses to form one large bed. π©ββ€οΈβπ¨
This results in a super-king-size bed, though it'd be a tad shorter than the standard super king-size bed dimensions UK - 180 x 190 cm versus 180 x 200 cm.
Your best bet would be getting a super king bed frame for the two singles.
Combining two single mattresses ensures that both partners have enough space to move comfortably and also allows for different firmness requirements to be met.
We'd highly recommend doing this for partners with a weight difference of 15 kg (33 lbs) or more or for partners with different firmness preferences.
There will be a slight gap between the two mattresses, which can be filled in with a bed bridge.
Alternatively, opting for a zip-and-link mattress like those sold by Dreams, where two mattresses can be zipped together, is a good option.
UK small double mattresses
The standard UK small double mattress has dimensions of 120 x 190 cm (4' x 6'3").
Small double mattress | |
Dimensions (W x L): | 120 x 190 cm (4' x 6'3") |
Best suited to: | Teenagers, students, young adults with limited bedroom size |
A small double mattress is a good option that falls between standard single and standard double mattresses.
These beds are a popular choice for teenagers, students, or young adults who often have budget and space constraints. πΈ
Some of the best budget mattresses, like the Simba Essential, are available in small double options.
Small double beds are also convenient for guest bedrooms.
UK double mattresses
The standard UK double mattress has dimensions of 135 x 190 cm (4β6" x 6β3β).
Double mattress | |
Dimensions (W x L): | 135 x 190 cm (4β6" x 6β3β) |
Best suited to: | Women, single adults, couples with limited bedroom space |
This is the most popular mattress for adults in the UK and will fit an average-sized bedroom.
It's a great option for singles wanting a bit more sleeping space and couples with smaller bedrooms.
The Emma Original is a fantastic double mattress for a great night's sleep.
That said, we wouldn't recommend a UK double mattress size to couples in the long term.
We'll elaborate on this in more detail further down. π
Since mattresses should be at least 10 cm longer than the tallest person using the bed, we also wouldn't recommend double mattresses to anyone taller than 180 cm (6'0").
UK king mattresses
The standard UK king mattress has dimensions of 150 x 200 cm (5β x 6β6β).
King mattress | |
Dimensions (W x L): | 150 x 200 cm (5β x 6β6β) |
Best suited to: | People taller than 180 cm, single adults, couples |
The king-size mattress is our preferred choice for couples. π
It offers enough space for two people to sleep comfortably.
But, it's also longer than average and better suited to people taller than 180 cm (6'0").
A mattress like the Nectar mattress, with good support and excellent motion isolation, is a fantastic king-size mattress choice for couples.
And since these bed-in-a-box mattresses are delivered rolled up, you won't have to worry about carrying a massive mattress into your bedroom. π
Single adults who like a lot of space or those sharing their bed with a young child or pet will also really enjoy the size of a king bed. π
UK super king mattresses
The standard UK super-king-size mattress has dimensions of 180 x 200 cm (6β x 6β6β).
Super-king mattress | |
Dimensions (W x L): | 180 x 200 cm (6β x 6β6β) |
Best suited to: | Couples, families, people of larger builds or heavier weights |
The super king mattress is the premium choice for couples.
It ensures that both partners have more than enough space to sleep comfortably without worrying that they'll disturb each other.
Super-king mattresses are also a good choice for people (and couples) of larger builds or heavier weights, or those with kids or pets that frequently hop into bed with them.
The Simba Hybrid is one of our top choices, offering premium comfort and support.
Unfortunately, super-king mattresses won't fit everyone's budget or bedroom size - but, with bed-in-a-box mattresses, you at least don't have to worry about carrying the mattress into your room.
This is because bed-in-a-box beds are delivered vacuum-packed and rolled up in a cardboard box that's pretty easy to manoeuvre through tighter spaces.
UK emperor mattresses
The standard UK emperor mattress measures 200 x 200 cm (6β6β x 6β6β).
Emperor mattress | |
Dimensions (W x L): | 200 x 200 cm (6β6β x 6β6β) |
Best suited to: | Luxury rooms, families, hotel suites |
The emperor bed is the largest mattress size available in the UK.
It is a luxurious choice that offers more than enough space and can be used quite comfortably by three people or more (parents, children, and pets). πββοΈπββοΈπ§πΆ
Emperor beds may be the largest standard size but they are not commonly available as bed-in-a-box mattresses.
The only bed-in-a-box brand that we know of that sells emperor beds is Otty.
You'll be more likely to find emperor-sized mattresses at traditional retailers. π
How do you choose the right mattress size?
You may have a vague idea about the size of mattress you need.
But actually deciding while you're hunting for a new mattress can be a little more complicated. π€―
There is no right mattress size.
Instead, the right mattress size for you depends on a variety of factors, including your height and body weight, the size of your bedroom or studio apartment, and your family setup.
The below questions can guide you:
- Are you short, tall, or of average height?
- Are you light-weight, of average weight, or slightly heavier?
- Do you sleep alone or do you share your bed with a partner?
- Do you have children or pets that share your bed with you?
- Are you a restless sleeper?
- If you have a partner, is your partner a restless sleeper?
- How big is your bedroom?
- How big/wide are your staircases, entryways, and corridors?
These questions may not give you a definitive answer, but they will help put you on the right path. β
It's also worth noting that bed-in-a-box brands give you the opportunity to try larger beds that traditionally wouldn't have fit through entryways or corridors.
This is very convenient for people with narrow staircases or those living in loft apartments where a larger bed may fit, but carrying it up would have been an issue otherwise.
You can also consider the following:
- If you're buying a replacement mattress, measure your current bed frame and bedding dimensions, and buy a mattress in the same size.
- If you're buying a bed & mattress for the first time or you want to upgrade your bedroom setup, consider your budget (also include costs of the bed frame and bedding) and the size of your bedroom, and choose from there.
These factors can act as a guideline to help you choose your new bed.
Don't forget to always consider the space around your bed as well - i.e. you'll still need space for bedside tables and ensure that the bed doesn't block any doors, windows, or power outlets.
If you're looking to buy a bed and mattress, it may be worth looking into a bundle deal.
These combine a bed frame with a mattress and fitting sleep accessories. π
These are some of our favourite bundle deals:
How wide should your mattress be?
If you're sleeping by yourself, the width of your mattress doesn't really matter too much. π€
You'd be able to sleep comfortably on most adult mattresses.
Of course, if you're a very restless sleeper and frequently toss and turn at night, a slightly wider mattress will be more comfortable. πΊ
Width becomes more of an issue, though, if you share your bed with a partner.
The double bed size, available from some of our favourite brands, like Nectar, is the most popular choice for adults in the UK.
But, this mattress is only 135 cm (4β6") wide - giving each partner only 67.5 cm (2'3") of space.
That's narrower than a toddler mattress! π³
Sure, if you're a snuggle bunny and you and your partner love being cosy with little room to move, this isn't a train smash.
But, it also means that you're more likely to disturb your partner every time you change sleep position, eventually resulting in poor sleep. βΉοΈ
This is one of the reasons we always recommend a mattress with good motion isolation, which ensures that movements aren't carried across the mattress.
This becomes even more of an issue if you take build and body size into account.
Here's a simple test to determine if a mattress is large enough for two people:
- Lie next to your partner on the mattress.
- Both of you should lie on your backs and put your hands behind your head, with elbows sticking out.
- If your elbows don't touch, the mattress is big enough and you'll have enough room to sleep comfortably.
- If your elbows touch, you'll need a bigger mattress.
If you and your partner are both on the smaller side, you wouldn't have much of a problem.
But if you're of average or above-average build, height, or weight, a double mattress will quickly become too small.
This is why we'd always recommend couples opt for a king-size bed or larger. π
One of our favourite mattresses for couples is the DreamCloud Luxury Hybrid.
It's large, luxurious, and oh-so-comfortable.
You can also read our full guide on the best mattresses for couples in the UK.
How long should your mattress be?
Your mattress should be at least 10 cm (3.9 inches) longer than the tallest person using the bed.
- Standard single and double beds only have a length of 190 cm (6'3").
- Standard king, super king, and emperor beds have a length of 200 cm (6'6").
If you're taller than 180 cm (5'9"), you should ideally opt for a bed with a length of 200 cm. π
In the UK, only the king, super king, and emperor mattresses have a length of 200 cm.
European mattresses, in contrast, always have a length of 200 cm, so if you're looking for a longer single or double bed, it'd make sense to opt for a brand like Simba that actually sells both UK and EU mattress sizes.
If you're taller than 190 cm (6'2"), though, it'd be best to invest in an extra-length bed for added comfort.
After all, you don't want your feet sticking out at the end of the bed. π¦Ά
How high should your mattress be?
The height or thickness of a mattress does not affect the overall mattress size.
To measure a mattress's size, we only look at the width and length of the mattress.
But, the thickness or height of a mattress affects the overall look and feel of your bed.
As a rule of thumb:
The thicker the mattress, the more comfortable and luxurious it will be.
Thicker mattresses also tend to last longer.
Here's a quick guide:
- For foam mattresses, we recommend a minimum mattress thickness of 18 cm (7 inches).
- For spring mattresses, we recommend a minimum mattress thickness of 23 cm (9 inches).
Most standard bed-in-a-box mattresses, like the Emma Original, have a height of 25 cm (10 inches).
This is a comfortable thickness that will look nice on any bed frame. π
Conveniently, this standard size is also practical as it ensures most bedding will fit!
But there are a few thinner, lighter options available, like the Eve Lighter mattress.
This mattress only measures 20 cm (7.8 inches).
Thinner mattresses are more budget-friendly and are a great option for children or guest bedrooms.
You may also wish to opt for a thinner mattress if your child or pet shares your bed and you don't want to risk them falling (or jumping) out and hurting themselves.
There are also a few thicker mattress options available, which are higher than the standard 25 cm.
The DreamCloud Luxury Hybrid, for example, has an average height of 28 cm (11 inches).
Thicker mattresses tend to give bedrooms a more luxurious feel. π
They can also be more convenient for the elderly, as it makes getting in and out of bed easier.
What size should your bed frame be?
Bed sizes UK & mattress sizes UK often go hand-in-hand.
Bed frames are available in a range of different UK bed sizes to match your chosen mattress.
If you choose a super king size mattress size UK, for example, you also need to purchase a super king size bed frame.
The standard bed sizes UK will include:
- Standard small single bed
- Standard single bed
- Standard small double bed
- Standard double bed
- Standard king bed
- Standard super king bed
Some frames aren't available in smaller sizes, so it's always a good idea to check out bed frames and mattresses at the same time.
Will my bed frame fit?
UK bed sizes may come with the same size descriptions as your mattress (such as small, double, or king size bed size UK).
But this does not mean that the bed dimensions will necessarily be the same as the mattress dimensions. π±
The dimensions of your frame will depend on the style of frame you choose:
- Divan beds or box springs (without a headboard) will have the same dimensions as your mattress since the mattress simply sits on top of the divan base.
- Wooden bed frames are usually slightly larger than your mattress, with a few extra centimetres on each side.
- Upholstered bed frames vary in size, depending on the shape of the frame and fabric used.
Always get accurate measurements of the space available to make sure your desired bed frame will fit and make sure the bed won't block any required power outlets, doors, etc. π
Don't forget to take into account the design of the headboard (thicker or curved headboards, like the one on the Simba Orion Bed, take up more space) and whether or not the bed has a foot end.
Beds like the Simba come flat-packed in boxes, so you just need to worry about the space in your room and not how wide your stairways, corridors, or doorways are.
This is super convenient for tight spaces or loft rooms.
Also, keep in mind how much space you'd need for bedside tables or if you need space on both sides of the bed for partners to climb in.
Those with minimal space should opt for a divan base without a headboard.
Some of our favourite UK bed frames:
What's the best mattress size?
As you've seen, there's not one best mattress size.
The right mattress size for you will depend on your budget, sleeping requirements, relationship status, and the size of your bedroom.
While you can opt for a few custom sizes, we'd highly recommend sticking to standard UK mattress sizes.
This makes finding suitable bedding a breeze.
Need some mattress recommendations?
Here are a few of our favourite UK mattresses:
Alternatively, message us directly via the Contact Us page.