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Last updated: July 2025
Choosing the right size bed and mattress is one of the most important decisions to make when updating your bedroom. To help you get it right, we've put together a handy guide to show how big each bed size is and which is best for your circumstances. Plus, to help clear the air of confusion, we've also included European bed sizes to make comparing easy.
6'6" x 6'6"
200 x 200
6'0" x 6'6"
180 x 200
5'0" x 6'6"
150 x 200
4'6" x 6'3"
135 x 190
4'0" x 6'3"
120 x 190
3'0" x 6'3"
90 x 190
2'6" x 6'3"
75 x 190
2'3" x 4'6"
70 x 140
23" x 47"
60 x 120
Choosing the right size bed and mattress is the first step towards a great night's sleep and a beautifully proportioned bedroom. In the UK, bed frame sizes are named after the mattress they're designed to hold, ensuring consistent dimensions across standard ranges (single, double, king, etc.).
To ensure a perfect match, your new mattress dimensions must align with your bed frame and, importantly, comfortably fit your height and room. Think about who’ll be sleeping in the bed and how they like to sleep - whether they sprawl like starfish or curl up tight. Make sure there’s plenty of room, with no feet dangling off the end. Below, we'll explore the standard UK bed and mattress dimensions and offer guidance on which size best suits each.
Remember, the overall footprint of your bed isn't just about the mattress. The style of bed frame you choose impacts its final dimensions, too:
Top tip: Always double-check the total external dimensions of the bed frame (not just the mattress size!) before buying. This ensures it will fit comfortably in your space, leaving ample space to move around. Use our home measuring guide to help.
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Emperor beds and mattresses are the largest, measuring 200cm wide and 200cm long. This is the largest bed we have available, which is perfect for families who like to squeeze in for breakfast in bed, or those who just value a lot of space!
Best for: two people or more and those who like extra room.
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Super king beds and mattresses dimensions are 180cm wide and 200cm long (6ft wide by 6ft 6in in length. Our super king mattresses are available in memory foam and pocket spring.
Best for: two people with some extra space.
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In metric measurements, a standard king size bed and mattress is 150cm wide and 200cm long (5ft wide by 6ft 6in long). King size beds and longer than double beds, making them perfect if you’re a taller person who needs the extra leg room, or for couples looking for a spacious upgrade.
Best for: two people and those taller than 190cm/6ft 2ins
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Double beds and mattresses are 135cm wide and 190cm long (4ft 6ins wide and 6ft 3ins long). As the most common size for a bed and mattress, doubles are ideal for two people and fit in most bedrooms. If you’re looking to maximise space in your bedroom, try a double ottoman bed for extra storage.
Best for: two people and small to average sized bedrooms.
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A small double bed and mattress is 120cm wide and 190cm long (4ft wide and 6ft 3ins long). Also known as a queen size bed, they are most suited to sleeping one person but can accommodate two adults if necessary. If your bedroom is smaller than average, small double beds are ideal, especially if you choose a divan or ottoman base which maximises storage space.
Best for: one person or couples with small bedrooms
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Single beds and mattresses measure 90cm wide and 190cm long (3ft wide and 6ft 3ins long). As the name suggests, they’re ideal for one person and small bedrooms. They’re also great for children as they are cheaper, but still account for all growth spurts from roughly 4 years of age right through to teens.
Best for: one person
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Small single bed and mattresses dimensions are 75cm wide and 190cm long (2ft 6ins wide and 6ft 3ins long). Small singles are designed to fit narrower kids' bed frames and guest beds. They’re ideal for saving space and for spare rooms.
Best for: Children from roughly 4 years’ old, small rooms and guest beds
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Toddler beds and mattresses are 70cm wide and 140cm long. (2ft 3ins wide and 4 feet 6 inches long). They're ideal for kids aged roughly between 1 and 4 years, especially those who need a little help changing from a cot to a single bed, as explained in our guide on how to choose your child’s first bed.
Best for: Toddlers and kids' character beds
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Cot mattresses are 60cm wide and 120 cm long (23ins wide by 47ins long). These mattresses are designed for babies who sleep in a cot and best for the sleep needs of babies from birth to 3 years old. They’re usually 10cm deep and are firmer than adult mattresses. This helps your baby’s development by helping to support their spine during sleep.
Best for: Babies and toddlers who haven’t yet moved into a bed
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Mattresses vary in depth depending on the manufacturer. The standard depth of a mattress is between 20-36 centimetres, which will accurately fit a standard fitted sheet for that bed size. Mattresses outside the standard depth range will require either shallower or deeper bedding to fit the mattress securely.
When choosing the right mattress depth for you, it’s important to consider the level of support you prefer, accessibility and appearance.
European bed and mattress sizes differ slightly to UK bed and mattress sizes, often being a little longer in size. It’s important to understand whether you have a UK or European bed frame before choosing a mattress to ensure it fits properly.
90 x 190cm (3'0" x 6'3")
90 x 200cm (3'0" x 6'6")
135 x 190cm (4'6" x 6'3")
140 x 200cm (4'7" x 6'6")
150 x 200cm (5'0" x 6'6")
160 x 200cm (5'3" x 6'6")
180 x 200cm (6'0" x 6'6")
Let's recap, because bed and mattress sizes can make a big difference in the quality of your slumber and the practicalities of your bedroom:
Discover which mattress is best suited to you depending on your sleeping position.
This helpful guide will show you the key differences between our popular mattress types and which type is best for you.
Whether you’re looking for a master bedroom centrepiece or the perfect bed for guests, find the right bed for every room with our helpful guide.