What Mattress Size Do I Need?
Mattress size is a personal choice, and the best option depends on who will be sleeping on the mattress, how much space you have available and how much room you like when you sleep.
If you sleep alone, a Single or Small Double may provide everything you need. Couples may prefer a Double, King or Super King, particularly if you like plenty of space to move around. You should also consider the size of your bedroom, access to the room and whether the mattress needs to fit an existing bed frame.
Who Will Sleep On It?
Think about whether the mattress will be used by one person, a couple, children or the whole family.
How Much Space?
Consider the bedroom dimensions and how much floor space you need around the bed.
How Tall Are You?
Taller sleepers may benefit from the additional 10cm length offered by King and Super King mattresses.
What Bed Do You Have?
Always check the internal dimensions of an existing bed frame before ordering a new mattress.
What Are the Standard UK Mattress Sizes?
The most common UK mattress sizes are Small Single, Single, Small Double, Double, King and Super King. You may also come across specialist sizes such as Emperor, Petite Double, Small Super King and European mattress sizes.
UK mattresses are traditionally described using imperial measurements, although dimensions are also commonly shown in centimetres. Please note that metric measurements are approximate conversions of the standard imperial sizes.
A compact single size, ideal for children's bedrooms and rooms where space is limited.
A popular choice for children, teenagers, adults and guest bedrooms.
A useful compromise for smaller rooms or solo sleepers wanting additional space.
A versatile and popular size for couples, guest rooms and larger single bedrooms.
A spacious option for couples, with an additional 10cm of length compared with a Double.
The largest common UK size, giving couples plenty of room to stretch out and move around.
UK Mattress Size Chart
Use the table below to quickly compare the most common mattress sizes available in the UK.
| Mattress Size | Width × Length | Imperial | Best Suited To |
|---|---|---|---|
| Small Single | 75 × 190cm | 2'6" × 6'3" | Children and compact bedrooms |
| Single | 90 × 190cm | 3'0" × 6'3" | Children, teenagers and single sleepers |
| Small Double | 120 × 190cm | 4'0" × 6'3" | Solo sleepers and smaller bedrooms |
| Double | 135 × 190cm | 4'6" × 6'3" | Couples and guest bedrooms |
| King | 150 × 200cm | 5'0" × 6'6" | Couples wanting additional space |
| Super King | 180 × 200cm | 6'0" × 6'6" | Couples wanting maximum sleeping space |
SMALL SINGLE · 2'6" × 6'3"
Small Single Mattress Size
A Small Single mattress measures approximately 75 × 190cm and is a useful space-saving option where a standard Single would take up too much room. It is particularly suited to children's bedrooms and compact sleeping spaces.
Its standard 190cm length means it can also accommodate some adults for occasional use, although taller or broader sleepers may find a wider mattress more comfortable for everyday sleeping.
Ideal For
Children, compact bedrooms and space-saving bedroom layouts.
Dimensions
75 × 190cm · 2'6" × 6'3"
Compatible Beds
Small Single bed frames and other compatible Small Single bases.
SINGLE · 3'0" × 6'3"
Single Mattress Size
A Single mattress measures approximately 90 × 190cm and is one of the most popular choices for children and teenagers. It also works well for adult single sleepers and guest bedrooms.
The Single provides enough room for one sleeper without taking up excessive floor space, making it a practical choice for smaller bedrooms.
A versatile size that can remain suitable as a child grows.
A practical option where occasional adult guests need comfortable sleeping space.
Leaves more usable floor space than larger mattress sizes.
SMALL DOUBLE · 4'0" × 6'3"
Small Double Mattress Size
A Small Double mattress measures approximately 120 × 190cm. Also sometimes called a three-quarter bed, it offers significantly more width than a Single while taking up less space than a standard Double.
It can be an excellent choice for a solo sleeper who likes additional room, a growing teenager, a compact guest room or a smaller bedroom where a Double would feel too large.
DOUBLE · 4'6" × 6'3"
Double Mattress Size
A Double mattress measures approximately 135 × 190cm and remains one of the most popular mattress sizes in the UK. It offers a good balance between sleeping space and bedroom floor space.
A Double can be used by two adults and is also a generous option for a single sleeper who enjoys plenty of room. If you regularly share your bed with children or pets, however, you may find a King more comfortable.
A popular everyday choice for two adults.
Provides a comfortable and versatile guest bed.
A great option if you prefer lots of room to move around.
KING · 5'0" × 6'6"
King Size Mattress
A King size mattress measures approximately 150 × 200cm. The extra 10cm of length compared with a Double can make a noticeable difference for taller sleepers, while the additional width gives couples more room to move.
King is an excellent choice if you share your bed and want additional space without moving all the way up to a Super King. It can also provide enough room for occasional weekend family cuddles.
SUPER KING · 6'0" × 6'6"
Super King Mattress Size
A Super King mattress measures approximately 180 × 200cm, giving you a generous 6 feet of width and 6 feet 6 inches of length. It is ideal for couples who want maximum sleeping space.
A Super King can be particularly appealing if you regularly share the bed with children or pets, or if you simply prefer plenty of room to stretch out. Before choosing this size, make sure your bedroom and access route can accommodate such a large mattress.
180cm of width gives couples plenty of personal sleeping space.
Best suited to bedrooms with enough floor space around the bed.
Measure doors, hallways, stairways and corners before ordering.
What About Emperor and Other Mattress Sizes?
Alongside the six standard UK sizes, some manufacturers and retailers offer additional or specialist mattress dimensions. These can include Emperor, Small Super King, Petite Double and European sizes.
Emperor
Approximately 200 × 200cm (6'6" × 6'6"). A very large square mattress designed for exceptionally spacious bedrooms.
Petite & Small Super King
Some suppliers offer less common dimensions for specific bed frames, so always check the exact measurements before ordering.
European Sizes
European mattress dimensions can differ from UK sizes, so European beds and mattresses should not be assumed to be interchangeable.
How Do I Measure My Bed Frame for a New Mattress?
If you're buying a mattress for an existing bed, the most important measurement is the internal space where the mattress sits. Do not measure the outside of the bed frame, as the frame itself can add several centimetres to the overall dimensions.
Measure the internal width where the mattress will sit.
Measure from the inside of the headboard area to the foot of the bed.
Make sure the existing base is level, supportive and suitable for the new mattress.
Compare your measurements with the exact mattress dimensions before ordering.
Will the Mattress Fit in My Bedroom?
The mattress fitting into the bedroom is only part of the equation. You also need to consider how the mattress will get into the property and into the room.
Bedroom Floor Space
Check that the mattress size leaves enough room to comfortably walk around the bed and open nearby doors and drawers.
Doors & Hallways
Measure doorways, corridors and any narrow points between the entrance and the bedroom.
Stairs & Corners
Pay particular attention to tight staircases, landings and sharp corners that may make manoeuvring a large mattress difficult.
How Long Should My Mattress Be?
Your height is another important consideration when choosing a mattress. As a general guide, you should have enough mattress length to allow your body to lie comfortably without your feet reaching the end.
If sharing a mattress, use the height of the tallest person when considering the required length.
Ideally, allow around 10cm of additional mattress length beyond the tallest sleeper.
King and Super King mattresses are 200cm long, giving taller sleepers more room than a standard 190cm mattress.
Do You Have Enough Sleeping Space?
Mattress dimensions tell you how large the sleeping surface is, but your own sleeping habits can help determine whether you need more room.
Stretch Out
Lie down naturally with your hands behind your head. If you regularly feel restricted by the edges of the mattress, you may benefit from a larger size.
Think About Movement
If you move around frequently during the night, additional width can give you more freedom to change position.
Consider Your Partner
Couples may need more width if both sleepers like to spread out or regularly share the bed with children or pets.
Quick Guide to Choosing Your Mattress Size
You're furnishing a compact children's room or need to maximise floor space.
You need a practical size for one child, teenager, adult or guest.
You're a solo sleeper who wants extra space without using a full Double.
You want a versatile size for two adults or a spacious single sleeper.
You're a couple who wants additional width and length for greater comfort.
You have the space and want the maximum amount of room to sleep.
10 Things to Check Before Buying a Mattress
Choose the size that suits your sleeping arrangements.
Make sure you have enough room to sleep comfortably.
Allow additional length for the tallest sleeper.
Measure the available floor space around the bed.
Check the mattress can be brought into the property.
Consider narrow staircases, landings and corners.
Measure the internal mattress area rather than the outside.
Check the mattress depth works with your bed and bedding.
Consider couples, children and pets sharing the bed.
Always compare the manufacturer's measurements before ordering.
Ready to Find Your Perfect Mattress Size?
Whether you need a compact Small Single, a practical Double, a spacious King or a luxurious Super King, choosing the correct mattress size is the first step towards creating a more comfortable bedroom.
Shop All Mattresses →Frequently Asked Questions About Mattress Sizes
What size is a King mattress?
A UK King size mattress measures approximately 150 × 200cm, or 5'0" × 6'6".
What size is a Super King mattress?
A UK Super King mattress measures approximately 180 × 200cm, or 6'0" × 6'6". It provides considerably more width than a King and is ideal for couples wanting additional sleeping space.
What is the most popular mattress size in the UK?
King size is a very popular choice for couples because it provides additional width and length compared with a Double while remaining suitable for many bedrooms.
What size mattress is best for a couple?
A Double can accommodate two adults, but couples who want more personal space may prefer a King or Super King. The right choice will also depend on bedroom size and budget.
What mattress size is best for a guest room?
A Single is a practical choice for occasional guests, while a Double can provide more flexibility for couples. A Small Double can be useful where bedroom space is limited.
How do I measure my existing bed for a mattress?
Measure the internal width and length of the area where the mattress sits. Avoid measuring the outside of the frame, as this includes the bed frame itself and will not necessarily indicate the mattress size required.
Will a mattress fit any bed frame of the same size?
Not necessarily. Although standard mattress sizes are designed around common dimensions, older, antique and non-standard bed frames can have different internal measurements. Always measure the space available before ordering.
How much longer should my mattress be than me?
As a general guide, around 10cm of additional length beyond the tallest sleeper can help provide comfortable room at the foot of the mattress.
Is a Small Double big enough for two people?
A Small Double is approximately 120cm wide and can accommodate two people, but it provides considerably less personal space than a standard Double, King or Super King. It is often better suited to solo sleepers who want additional room.
What is an Emperor mattress?
An Emperor mattress is a specialist large mattress size, commonly around 200 × 200cm. Exact dimensions can vary between manufacturers, so always check the specific measurements before purchasing.
MORE EXPERT ADVICE
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