Double Mattress Advice Guide

Knowing which size mattress is the right one for you can be difficult, so if you’re considering a double mattress, we have all of the information you need to make the correct choice.

Here we explain double mattress size dimensions, the types of double mattresses available as well as the price ranges of double mattresses at Mattress Online.

We also answer some of the most frequently asked questions from our customers.

Browse our double mattresses today

Woman reading on her laptop while sat on her double bed.
Find out everything you need to know about buying a double mattress below.

What size is a double mattress?

All UK standard double mattresses are the same size - 135cm x 190cm - however, you may notice some variations of the double mattress size while browsing online.

Below are the different variations of double mattresses you can buy, along with their dimensions.

Mattress sizeMetric measurementsImperial measurements
UK standard double mattress135cm x 190cm4'6" x 6'3"
Small double mattress120cm x 190cm4' x 6'3"
European double mattress140cm x 200cm4'7" x 6'6"

The size you buy will depend on the dimensions of your bed. A mattress that does not fit snugly on to your bed base can cause damage to both your mattress and the bed. This can negatively affect the quality of your sleep.

Shop all mattress sizes today


Below we’ve answered some quesions that our customer have frequently asked around double mattress sizes:

How wide is a double mattress?

A UK standard double mattress is 135cm (4'6") wide.

How long is a double mattress?

A UK standard double mattress is 190cm (6'3") long.

Is a double bed OK for 2 adults?

Yes, a double mattress is suitable for two adults. However, a double is the smallest size meant for two people. If you and your partner both like a bit of extra space to spread out, a king size mattress is a better choice.

What size bed do most couples sleep on?

Most couples sleep on either a double bed and mattress or a king size bed and mattress.

A double bed can feel quite snug with two adults; you will both have 65.7cm of space each to sleep - which is actually less space than a baby has in a standard 70cm wide cot bed!

A king size bed and mattress will give you an extra 7.5cm each in which to spread while you sleep.

What age should you get a double bed?

This is completely up to you! Many people progress from a single bed to a double bed in their early teenage years as they grow and want more space to spread out while they sleep.

However, if you don’t have the space for a double bed, an adult who lives alone will find a single or small double bed more than comfortable.

Should I get a single or double bed?

This is entirely your choice. Here are some questions you can ask to help you decide:

  • Do you share your bed with a partner?

If yes, a double bed will be more suitable for you as two adults cannot comfortably fit in a single bed.

  • Do you have enough space to fit a double bed in your room?

You want to make sure that you still have enough space in your bedroom to comfortably walk around your bed. If you do not you should opt for a single or small double bed instead.

  • Do you find your single bed too small?

If you currently sleep on a single bed, do you find yourself rolling uncomfortably close to the edge of the bed in the night? Or do you tend to sleep with your arms and legs hanging off of the side of the bed? If the answer is yes, you may benefit from moving up to a double bed.

The Silentnight Geltex Ultra 3000 Mirapocket Firmer Mattress on a fabric bed in a blue, teenagers room.
The Silentnight Geltex Ultra 3000 Mirapocket Firmer Mattress is one of our most popular double mattresses!

We hope this has helped you choose the right bed for your needs! If you’re looking for a size half way between a single and a double, why not check out a small double mattress or bed?

Browse our double mattresses

Small double

Small double mattresses and beds have grown in popularity over the last decade.

They are perfect if you’re looking for something slightly longer and wider than a single mattress, but not as large as a double.

Small double mattresses measure 120cm x 190cm (4' x 6'3").

Sealy Steeple Ortho Plus Mattress in a white and yellow bedroom.
The Sealy Steeple is one of our best-selling small double mattresses.

Euro double

European double mattresses and beds are slightly longer and wider than UK standard double mattresses. They are the same width as a standard UK king size mattress.

European double mattresses measure 140cm x 200cm (4'7" x 6'6").

Classic Gold Ortho Mattress
Our best selling European double mattress: The Classic Gold Ortho Mattress


‘Queen size’ is actually an American size term, which is why you may not be able to find this size while browsing in the UK.

It is slightly bigger than a UK standard king size mattress and it’s dimensions are 152cm x 203cm (5’ x 6’6”).

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Fitting the right mattress to the right frame

Here are some common questions around pairing mattresses with different sized beds:

Can you put two single mattresses on a double bed?

No, you cannot put two single mattresses on a double bed. Two singles are wider than a double frame. The mattresses would hand over and you would fall off.

Single mattresses measure 90cm (3 feet) wide and double beds measure 135cm (4 feet 6 inches) wide.

We do not recommend putting more than one mattress on a bed, even if it did fit the measurements of the bed base. Doing this could damage the mattress and your bed and affect your warranty or guarantee.

Will a double mattress fit a small double bed?

No, a double mattress will not fit on a small double bed.

Double mattresses are 15cm wider than small double beds. Using a mattress that is too large for your bed can cause greater wear and tear on your mattress.

As double mattresses are heavier than small double mattresses, you could also damage your bed base as the frame may not be designed to hold this weight.

Buy a small double mattress today

Will a double mattress fit a king size bed?

A double mattress will fit on a king size bed, but we do not recommend pairing them together.

A double mattress is 15cm narrower and 10cm shorter than a king size bed. Using a mattress that doesn’t perfectly fit your bed base can cause it to slide into the frame, which may result in unnecessary damage to the mattress. The movement can also affect your quality of sleep.

A man measuring a slatted bed base for a new mattress.
Always remember to measure your bed base to make sure your new mattress fits perfectly.

We hope we’ve been able to answer all of your questions so you can find the best one for you!

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Weight & depth of double mattresses

Even though double mattresses have the same width and length dimensions, their depth and weights vary between each model of mattress.

Weight and depth can be useful measurements to know. All bed frames have a maximum weight limit. Some bed frames can also be much deeper than others.


We answer the most asked question about double mattress weight below:

How much does a double mattress weigh?

The average weight of a double mattress is between 30-40kg. However, we do stock much lighter and heavier mattresses. The weight range given here is only a rough guide.

The weight of a double mattress depends on the materials used to create the mattress. If your mattress has more springs or layers of foam than the average mattress, then you should expect its to be much heavier.

If you have any concerns or questions around the weights of our mattresses, please get in touch!


Like with mattress weight, the depth or thickness of a mattress varies between models. Here we’ve answered some of the most common questions around double mattress depths:

How thick should a double mattress be?

There is no right, wrong or ideal thickness for a double mattress, it’s all down to your own personal preference and the height of the space in your bed frame that accommodates the mattress.

Mattresses with a thicker depth tend to be more premium and luxurious while thinner mattresses are more budget. This is not always the case, but is a good rule of thumb.

If you’re looking into buying a double pillow top mattress, then you should take into account that they are much thicker than standard mattresses. This is because the pillow top layer adds an extra few centimetres of height to the mattress.

Which is better 6 inch or 8 inch mattress?

No one mattress depth is better than another because it is all down to personal preference. Many people associate thicker mattresses tend with greater luxury, although this is not always true.

The main things that you should take into consideration when buying a mattress are as follows:

These factors will give you a much better indication of the quality of the mattress than its depth.

Do thicker mattresses last longer?

No, thicker mattresses do not last longer.

All mattresses should be replaced after seven years to ensure that you are still getting the best night’s sleep out of your mattress.

A close up of the side of the SleepSoul Cloud 800 Pocket Memory Pillow Top Mattress.
Looking for a deep mattress? Check out the SleepSoul Cloud 800 Pocket Memory Pillow Top Mattress.

Now that you know all about the importance of mattress weights and depths, why not find out which double mattress type is the right fit for you?

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Double mattress types

No matter what type of double mattress you prefer, we have the perfect option for you. We’ve broken down the types of mattresses so that you can see which comfort and support layers most suit your sleep needs.

If you’re looking for a more in-depth guide on how to choose the perfect mattress for you based on your sleeping position, check out our helpful advice guide.

Mattress Online stocks mattresses from all the top leading brands with fantastic discounts, so you can get a better night’s sleep at a great price!

Synthetic mattresses

Synthetic mattresses are mattresses made from materials such as:

Or any other man-made substance. 

They often provide higher levels of support and pressure relief than other types of double mattress. These materials - especially memory foam, latex and gel - are created to mould to the shape of your body and provide personalised comfort and support exactly where you need it most.

Sealy Claremont Advantage Divan
The Sealy Claremont Memory Advantage Mattress double mattress offers fantastic pressure relief.

Check out our double mattresses today!

Sprung mattresses

There are two types of mattresses with springs for you to choose from:

These mattresses contain springs that are paired with a cushioning layer to give you a well-supported night’s sleep.

Pocket sprung double mattresses contain individually nested springs that independently react to your weight as you move in the night, providing responsive support.

We stock mattresses with pocket spring counts from 800 all the way up to 8,250 - so you can be sure to find the perfect mattress firmness for you!

Standard sprung double mattresses work slightly differently as every spring is interconnected. This can provide greater levels of firmness.

We’ve answered some common questions that customers ask about pocket sprung double mattresses:

How many pocket springs are in a double mattress?

The pocket spring count displayed in a product name refers to the amount of pocket springs in a king size of that particular mattress. For example, the ‘Luna Memory 1000 Pocket Mattress’ will have 1,000 pocket springs in its king size.

The exact number of pocket springs in a double mattress will also vary depending on the mattress model and manufacturer.

How many springs should a double mattress have?

As explained above, there is no ‘perfect amount’ of pocket springs that a double mattress should have.

What’s important is that your chosen mattress delivers the right amount of comfort and support for your personal needs.

Sometimes a mattress may have less springs, but the springs it has might have more spring tension. This could make the mattress feel firmer than a model that has hundreds of more springs of less tension.

You can find out more about sprung mattresses in our detailed pocket sprung and standard sprung guides.

Take a look at our pocket sprung mattresses

Hybrid mattresses

Hybrid mattresses often combine the best of synthetic and pocket sprung layers for a more specialised night’s sleep.

The most common hybrid mattress type pairs memory foam comfort with pocket sprung support. This combines the cushioning and pressure-relieving qualities of foam with the benefits of individually responsive springs.

The Simba Hybrid Essential 1500 Pocket Mattress has the best of both memory foam and pocket sprung support.

Natural filling mattresses

Natural filling mattresses are a traditional style of mattress. They have a pocket sprung support layer and a comfort layer that is one of the following materials or a blend of two:

  • Wool
  • Silk
  • Cashmere
  • Mohair
  • Silk
  • Cotton

These double mattresses tend to have a more luxurious feel to them and are often more breathable than synthetic mattresses due to their natural comfort layers.

The Hypnos Banbury Cotton Comfort Mattress in a modern, bright room.
Treat yourself to the Hypnos Banbury for premium double mattress comfort.

Pillow top mattresses

Pillow top mattresses are the ideal choice if you’re looking for luxurious comfort you can sink in to.

The cosy and sumptuous feel comes from the additional layer that’s on top of the mattress.

This does give your mattress an extra bit of height, so you may need to invest in some deeper fitted sheets if you choose to buy a double pillow top mattress.

The SleepSoul Space 2000 Pocket Memory Pillow Top Mattress on a black metal bed in a dark blue bedroom.
Sink into bliss with the SleepSoul Space 2000 - it's even a Which? Best Buy!

Rolled mattresses

As the name suggests, these rolled mattresses arrive at your house pre-rolled and packaged in a box for you to easily carry to your room of choice.

Please note: You cannot re-roll a rolled mattress once it has been unrolled.

The Emma Original Mattress with a Which? Best Buy for June 2021 and a Top 10 Recommended Mattress for 2022 badge.
The Emma Original is a great double mattress option that arrives at your house in an easy-to-move box.

Buy a rolled mattress today

Orthopaedic mattress

If you’re looking for a new mattress that prioritises back care and support, an orthopaedic mattress may be the best option for you.

These mattresses are usually one of the following firmnesses:

The greater firmness means that more pressure is relieved from your joints as you sleep.  The mattress provides additional quality support to the heaviest areas of your body: your hips, shoulders and lower back.

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Firmesses of double mattresses

Mattress firmness is one of the most important factors when choosing your new double mattress.

We offer a variety of firmnesses for double mattresses to suit every type of sleeper:

No matter how soft or firm you like your double mattress, we’re guaranteed to have the right firmness for you.

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When it comes to buying a double mattress we have a fantastic selection of the best mattress brands on the market, ranging from budget to premium.

  • Silentnight
  • Sealy
  • Sleepeezee
  • Emma
  • Simba
  • Millbrook
  • Rest Assured
  • Relyon
  • Dunlopillo
  • Harrison Spinks
  • Hypnos
  • Romantica
  • Dormeo
  • SleepSoul
  • Elle
  • Horizon
  • Luna
  • Bodyshape

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Price of a double mattress

Here at Mattress Online we have a huge range of double mattresses to suit all budgets. From budget brands to some of the most luxurious mattresses available, we have it all.

The prices for our double mattresses vary based on the manufacturer and the materials used to create the mattress.

Our cheapest double mattresses usually start at around £190 - and sometimes even less if you catch them in a sale!

Our most premium double mattresses can cost anywhere from £1,000 to £2,700. (These prices are subject to change.)

Why not take a look at our extensive range of double mattresses today?

All double mattresses

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Types of double beds

We don’t just have a great selection of double mattresses, we also have a lot of double beds for you to choose from:

Whether you’re looking for a statement bed for your master bedroom, a fun bed for your kids or cosy bed for your guests, we have it all.

All double beds

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Accessories for double mattresses

To top off your sleeping experience, why not invest in an accessory for your double mattress? We offer the following in double sizes:

Mattress protectors

Mattress protectors are a great way to keep your double mattress in perfect condition. They also help to keep your guarantee and warranty intact in case of any spills and accidents.

Protect your double mattress with the Protect A Bed Essential Mattress Protector!

Mattress toppers

Like mattress protectors, mattress toppers sit on top of your double mattress. They provide both protection and an extra layer of cushioning luxury. 

Double mattress toppers have the same measurements as a double mattress - 135cm x 190cm. Using a topper that is smaller or larger than this won’t give you an optimum sleeping experience. 

For example, using a small double mattress topper on a double mattress puts extra tension on both the mattress and the topper. This can damage the fillings in the topper and cause greater wear and tear on your mattress.

Silentnight Deep Sleep Mattress Topper
Add a little extra luxury to your new double mattress with the Silentnight Luxury Deep Sleep Ultimate Mattress Topper

Why not bring new life to your sleeping environment by investing in new duvets and pillows? Adding a little extra bedding is a cosy and relaxing way of giving your bedroom a makeover.

Shop all accessories and bedding today

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Here are some useful FAQs that our customers have asked which we think may help you:

Can you fit a double mattress in a car?

If you’re moving your mattress to another location and still plan to use it, you should transport your mattress flat. This means that a double mattress will not fit in a typical 5 door car, such as a Ford Fiesta or a Vauxhall Corsa. 

The average boot width of a car is 1.7m-1.9m wide, which is wide enough to accommodate the width of a UK standard double mattress, but double mattresses measure 1.9m in length, which is longer than the majority of most car boots.

If you’re looking to dispose of or recycle your mattress at a council-approved facility, you can fold your mattress up smaller if needed.

If you’re looking for how to correctly store your double mattress in transit, check out our helpful storage advice page.

Will a double mattress fit in a van?

Yes, a double mattress will fit in the boot of most standard work vans.

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We hope we’ve answered all your questions about double mattresses! Why not browse through our fantastic collection of double mattresses today?

If you’re still not sure which mattress will be the perfect fit for you, check out our handy helpful guide to find the best mattress type for your sleeping position.