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The bed and mattress size guide

Last updated: May 2024

Choosing the right size mattress for your bed

You’ll need to ensure the length and width of your new mattress matches your frame or base. Which size bed and mattress is right for you depends on the room it's going in and how many people will be using it each night. Below we’ll explore the dimensions of each UK bed and mattress size plus advice for who each size is best suited.

Mattress size vs bed frame size

When buying a new bed, you'll want to ensure it fits in your room comfortably, so you'll need to know which bed frames tend to have larger dimensions. These are often metal and wooden bed frames, as the mattress sits within the frame rather than on a base. However, we advise you to always check the dimensions of any product before making your purchase.

For more help choosing the right bed, take a look at our guide to buying a bed. Kids' also beds have a recommended mattress size to fit the bed frame, whether cot, single or Euro single.

Bed frame size according to style

The dimensions of your bed will differ depending on which style of bed frame you choose:

  • Divan beds without a headboard will have the same dimensions as your mattress, as it will sit flush on top of the divan base.
  • Wooden bed frames are usually a few centimetres bigger than your mattress around each side.
  • Upholstered bed frame dimensions differ a lot depending on whether they have a sleigh shape, the amount of detail, and the fabric.

Always check the dimensions of the bed before purchasing to ensure it fits in the room with enough space to move around the sides.

What size is a super king bed and mattress?

Super king beds and mattresses dimensions are 180cm wide and 200cm long (6ft wide by 6ft 6in in length. 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! Our super king mattresses are available in memory foam and pocket spring.

Best for: two people or more and those who like extra room.

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What size is a king size bed and mattress?

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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What size is a double bed and mattress?

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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What size is a small double bed and mattress?

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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What size is a single bed and mattress?

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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What size is a small single bed and mattress?

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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What size is a toddler mattress?

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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What size is a cot bed and mattress?

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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How do UK mattress and bed sizes compare to Euro ones?

A standard European single bed, often known as a twin bed, is 90cm wide and 200cm long. (3ft wide and 6ft 6ins long). This means Euro twin beds and mattresses are a little longer than their UK counterparts but the same width.

As a UK-based retailer, we don't stock Euro beds or mattresses, but, you can shop our range of similar sized single beds and single mattresses.

We do, however, stock a small range of Euro single mattresses for kids.

Things to remember when choosing a bed and mattress size

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:

  • Always think about your comfort. Do you like to spread out when you sleep? Do you sleep with a partner or pets who like to share the bed? If so, you'll want to make sure you choose a size that provides plenty of room for everyone to stretch their legs.
  • Don't forget about style. Finding the perfect size is key to creating a cosy retreat - one where you can relax and have enough room to manoeuvre around your bed. Whether that be through finding the best colour matches to work with, or bringing the latest style trends into your bedroom, the choice is yours.
  • And, finally, if you're shopping for a kid's bed, keep in mind how fast they grow. It may be worth investing in a larger size that will last them through their teenage years.