Best Cot Mattresses For Babies & Children

Best Cot Mattresses UK (2024)

Last updated: 31.10.2023 Reading time: 9 Min.

Having a good mattress is important to adults - but what if you have a baby, toddler, or young child?

Are there specific cot mattresses to consider?

Do baby mattresses differ?

What about health & safety?

In this article, we'll guide you through this very important subject and recommend some of the best cot mattresses available in the UK.

Let's get straight to it.👇

Best Mattresses for Babies and Children
Silky Soft

The Little Green Sheep Natural Twist Cot Bed Mattress

The Little Green Sheep Natural Twist Cot Bed Mattress is a 100% natural dual-sided cot mattress.

Made from natural, organic materials, this mattress contains coconut coir, latex, cotton, and wool.


The Little Green Sheep Natural Twist Cot Bed Mattress is one of the best baby mattresses available in the UK.

This is a dual-sided mattress.

The firmer side is recommended for babies up to 12 months, after which you can flip the mattress around to the more medium-firm natural latex side, more suitable for toddlers up to the age of 5. 

little green sheep mattress

The mattress is 100% natural and contains breathable cotton, supportive coconut fibres, comfortable natural latex, and a temperature-regulating wool layer. 🥥

All the materials are breathable, hypoallergenic, and free from any harmful chemicals and toxins. 

The coconut fibres and natural latex in the mattress core act like tiny springs, adapting to your baby's body.

The wool layer wicks away moisture and creates an environment resistant to dust mites and bacteria. 💨

On the downside, the mattress cover is not waterproof or removable, so we highly recommend you invest in a waterproof cot bed mattress protector.

The Little Green Sheep Natural Twist cot mattress is available in the standard 140 x 70 cm option, but you'll also find a smaller 120 x 60 cm size.


  Little Green Sheep Natural Twist
Materials: Cotton, coconut coir, natural latex, wool
Height: 10 cm (3.9 inches)
Size: 60 x 120 cm (1'9" x 3'9"), 70 x 140 cm (2'3" x 4'6"), also large selection of custom sizes available
Guarantee: 5 years
What we love: 100% natural; dual-sided; durable
What could be improved: Mattress cover not waterproof or removable 

Obaby Natural Coir Wool Cot Bed Mattress

The Obaby Natural Coir Wool Cot Bed Mattress is made of coconut coir, latex and lamb's wool.
  • Coconut coir, latex & lamb's wool
  • 10 cm (3.9")
  • Great for allergies 

Tell me more about the Obaby Natural Coir Wool Cot Bed Mattress

The Obaby Natural Coir Wool Cot Bed Mattress is a 100% natural and organic mattress.

It features a core of coconut coir bonded with latex, wrapped in lamb's wool.

Lamb's wool protects against dust mites and has temperature-regulating properties.

The Obaby Natural Coir Wool Cot Bed Mattress is also hypoallergenic and perfect for babies who struggle with allergies. 

The mattress comes with an antibacterial organic bamboo cover, which is removable and machine-washable.

It's also eco-friendly, fully biodegradable, and as good for the environment as it is for your little one. 

Reasons to buy


100% natural

5-year guarantee

Reasons to avoid

Some found it too soft for newborns 

Luxury Option

Simba Hybrid Cot Bed Mattress

The Simba Hybrid Cot Bed Mattress includes award-winning hybrid technology to create a dual-sided cot mattress.
  • Simba Renew™ fibres & Aerocoil® springs
  • Dual-sided design
  • Suitable for 1 - 3 years 

The Simba Hybrid Cot Bed Mattress revolutionises sleep for little ones, designed with an 8-layer structure to accommodate newborns and toddlers.

Its double-sided feature offers a firm, flat surface essential for babies under 12 months, ensuring safety from bacteria, allergens, and chemicals.

The other side offers cushioned support for toddlers aged 12 months to 3 years, revealing a cushioned support tailored to their growing needs, complete with edge-to-edge stability.

The Simba Hybrid Cot Bed Mattress has a water-resistant inner layer and a machine-washable for enhanced durability. 

Reasons to buy

2-year guarantee

Machine-washable cover

Suitable for newborn to toddlers 

Reasons to avoid

Very expensive 

What is a cot mattress?

Like adults, children need quality bedding and a quality mattress that meets their needs.

We would even go as far as saying that a quality mattress at this age is more important.

After all, babies sleep an average of 13 - 16 hours [1] a day. ⏰

A good mattress for young children will provide excellent support by adapting to your baby's body without creating painful pressure points.

Cot mattresses are specifically designed for children under the age of 6.

They aim to support the spine and provide for healthy spinal alignment. 🦴

This is essential for children in the growth period.

Mattress for babies and kids

Children will rarely complain about back pain at a young age, but a low-quality mattress may lead to back problems years down the line and only emerge in adulthood.

A good mattress will also provide quality sleep, which is key to your child's physical and mental recovery.

This will allow for a better capacity for concentration, memorisation, and learning during the day.

How to choose a cot mattress

Finding that perfect fit for your baby or young child shouldn't be too difficult, but there are a few criteria you need to consider.

These are important to ensure that the cot bed mattress you choose is the best to aid your little one's development. 👌

What mattress material should you choose?

Baby cot mattresses can be made from various materials, including pocket springs, coir, natural latex, or memory foam.

Important questions to ask yourself:

  • What is my budget?
  • How concerned am I about chemicals?
  • Do I want to go natural and organic?

There are cot bed mattresses to suit all of your requirements.

The most common cot bed mattress materials include:

Cot mattress materials

Many baby mattresses are made of certified foams, guaranteeing that they are free from harmful chemicals and toxins.

Cot mattresses made of natural and organic materials are also common. 🌱

These tend to be anti-allergy and free from harmful chemicals.

Natural and organic mattresses are often much more expensive, though, so you need to find the best cot mattress within your price range.

Mattress materials

How firm should the cot bed mattress be?

Firmness is an essential aspect to consider when choosing a mattress for your baby or toddler.

You need a mattress that offers good support but is also very comfortable

As adults, we're used to choosing firmness according to our sleep position and our body weight/size. ⚖️

For young children, firmness is a lot simpler.

  • Newborns usually require firm mattresses.
  • Toddlers will usually be more comfortable on medium-firm mattresses.

Medium-firm to firm mattresses will adequately support spinal alignment and aid healthy bone development.

Firm mattresses are also recommended by the Lullaby Trust [2]:

A firmer mattress is vital to meet safety standards.

If a cot mattress is too soft and your baby accidentally rolls onto the stomach, he or she could sink into the foams too much, which poses a suffocation risk.

Babies should always be placed on their backs to sleep, especially within the first six months.

Does breathability matter?

Yes, breathability is vital for a number of reasons:

  • It keeps your little one cool and comfortable for a better night's sleep.
  • It prevents the formation of mould and keeps the cot mattress more hygienic.

You should choose a cot mattress that allows for good airflow. 💨

But you also need to consider the mattress cover and your actual cot bed.

The mattress cover should be breathable and allow for good air circulation.

This will enhance the flow of air through the actual mattress.

Cot mattress covers

We would also recommend choosing slatted frames as these assist in keeping the cot bed mattress well-ventilated.

A note on cot bed deaths:
A cool mattress not only keeps your baby more comfortable - but it's also safer.
Babies who get too hot while sleeping have a higher chance of suffering from sudden infant death syndrome (SIDS).

Cot mattress safety standards

Health and safety are always important when choosing a new mattress, but even more so when choosing a mattress for your baby.

We recommend that you favour anti-allergenic materials free from harmful substances such as dichlorobenzene, nitrosamines, or formaldehyde.

This will allow your child to breathe more easily and avoid the risk of allergies. 🤧

External certifications

Look out for mattresses that have been certified by external testing institutions.

The two main ones include:

  • Certi-PUR certification [3]: This is a North American quality certification for foams. Certified foams have been independently tested in laboratories and certified as safe products.
  • Oeko-Tex Standard 100 Class 1 certification [4]: This is a European label that guarantees textiles are free of toxic products. This includes toxins for the body and for the environment.

Mattress foam certifications

Both of these certifications guarantee that the materials are free from harmful chemicals.

Since Oeko-Tex is an EU certification system, though, it's not always possible to find mattresses with Oeko-Tex certified foams in the UK. 🇪🇺

Certi-PUR certification is more common.

British Safety Standards

You can also rely on British Safety Standards.

A cot mattress that complies with British standards will have to meet certain criteria.

These include:

  • BS 1877-10:2011+A1:2012 specifies the kinds of materials, construction, and dimensions required when manufacturing mattresses.
  • BS 7177:1996 guarantees it has passed flammability standards.
  • BS EN 16890:2017 encompasses a wider set of tests and risks than the current mandatory standard, considering elements such as whether or not parts of the mattress can detach and become a choking hazard or if the mattress is too soft and likely to cause suffocation if your baby accidentally rolls onto the stomach.

Cot mattresses should meet at least the BS 1877 and BS 7177 standards. 👌

Organic certifications

Natural and organic cot bed mattresses are very popular these days. 🍀

They're often better for your baby and tend to last longer.

Organic mattress certifications

But, not everything that says organic is actually organic - that's why looking at organic certifications matters.

Two of the most common organic certifications include:

  • Certified GOLS [5] (Global Organic Latex Standard): This certifies that latex is produced in an environment where all materials and manufacturing processes meet strict global organic standards.
  • Certified GOTS [6] (Global Organic Textile Standard): This certifies that materials are produced in an environment where all materials and manufacturing processes adhere to strict global organic standards.

Mattress brands carrying these certifications are usually proud to advertise the fact, so getting the right info shouldn't be too difficult.

Sometimes, only certain materials are certified.

The Little Green Sheep Natural Twist Cot Bed Mattress, for example, carries the GOTS certification for some materials.


Cot mattress sizes

Luckily, there aren't as many cot bed mattress sizes as there are adult mattress sizes.

We'd suggest going for a slightly bigger mattress that will fit your bed frame best.

Your child will grow very quickly in the first few years, and you certainly don't want to have to buy a new mattress every other year.

There are two common cot mattress sizes:

  • Cot mattress 60 x 120 cm (1'9" x 3'9")
  • Cot mattress 70 x 140 cm (2'3" x 4'6")

While you may find a few custom sizes, we'd suggest sticking to the standard cot mattress sizes, 120x60 cm and 70x140 cm. 🇬🇧

This will make finding suitable accessories much simpler.

The standard sizes are also small enough to be suitable for a young child but large enough to accommodate a growing child.

UK kids mattress sizes


Always choose a mattress that fits your cot bed perfectly.

There shouldn't be any gaps (or no gaps wider than 3 cm / 1.1 inches) between the mattress and the cot frame, which could present a safety risk for your child.

How thick should a cot mattress be?

Most cot bed mattresses are 10 cm (3.9 inches) thick.

Travel cot mattresses are often a little thinner, but your baby shouldn't sleep on these every night.

We wouldn't recommend a cot bed mattress with a height under 8 cm (3.1 inches).

Mattress sizes for children over 6

As your child grows larger or passes the age of 6, you can switch over to an adult mattress.

We recommend a few of the best mattresses in the UK below. 👇

There's no right or wrong mattress size for children above the age of 6, though most people tend to opt for one of the following:

  • Small single mattresses sized 75 x 190 cm (2'6" x 6'3")
  • Single mattresses sized 90 x 190 cm (3’ x 6’3”)
  • Small double mattresses sized 120 x 190 cm (4' x 6'3")

The one you choose will depend on your budget, the size of your child's bedroom, and the bed frame you decide on.

Our favourite adult mattresses:

How to a clean a cot mattress

Children are very vulnerable to allergies - and nighttime accidents.

That's why paying attention to the hygiene features of a cot mattress is so important. 🛀

Some mattresses come with antibacterial treatments to help prevent the build-up of dust mites or bacteria.

Others have removable and machine-washable cot bed mattress covers.

Some also have both.

Cot mattress cover features
Cot mattresses have various hygiene features

And, again, others come with waterproof layers to help protect the mattress's core.

Regardless of the construction of the actual mattress, we'd always recommend purchasing a waterproof cot bed mattress protector.

Mattress protectors will help safeguard against moisture, spills, or stains - and elongate the mattress's lifespan.

Cot beds

While choosing the right mattress for your baby or young child is important, you also need to consider the bed frame.

This will significantly affect your choice of mattress as well.

There are no right or wrong choices, and what you end up choosing largely depends on your budget and personal preference.

Cot beds
There are many different types of cot beds available

Moses baskets

Moses baskets, cribs, or co-sleepers have been specifically designed for newborn babies. 👶

These take up much less space than a cot and are great if you have a smaller room and want your child sharing the room with you.

This is actually recommended for the first six months.

Moses baskets can also be carried around from room to room, which can be convenient.

But, you will have to invest in a crib mattress and then re-invest in a cot mattress as your baby grows.


Newborns don't have to sleep in a Moses basket or crib and can be quite comfortable in a cot as well.

This is handy as you can buy a cot and cot bed mattress once and then won't have to re-buy a new mattress or frame as your child grows. 🥳

Cots double nicely as toddler beds.

Baby mattresses can be expensive if you end up having to repurchase them again and again as your child grows.

It's a much cheaper and more sustainable option to invest wisely the first time around.

We'd also recommend a cot with slatted frames, as this will help with airflow and keep your baby's cot mattress well-ventilated. ❄️

Travel cot mattresses

Many parents choose to invest in a travel cot with a travel cot mattress or foldable travel cot mattress.

You could also invest in something like the Najell Babynest SleepCarrier, which is perfect for home and travel use.

This is a great idea if you're planning on travelling and need the convenience of a foldable cot. 🧳

But, we wouldn't recommend using a travel cot as a long-term solution.

Travel cot mattresses are usually smaller and thinner than regular cot mattresses.

Standard travel cot mattress sizes include:

  • Travel cot mattress 120 x 60 cm
  • Travel cot mattress 95 x 65 cm

Travel cot mattresses are usually between 5 and 10 cm in depth.

That's fine for occasional use, but not great for long-term use. 🗓

Our favourite travel cot mattresses:

What else do babies need?

Your cot bed mattress isn't the only important factor to consider.

Babies often don't need bedding (esepcailly if they're under one year old), but you may need to consider some other options to keep your little one comfortable.

Here are some of our favourite baby products:

What is the best cot bed mattress?

In general, you need to consider the health, safety, and development of your child.

The ideal cot mattress will offer comfort and support while aiding spinal alignment and healthy bone development.

You'll be good to go with any of our recommended mattresses.

Don't forget that bed-in-a-box mattress brands generally offer risk-free trial periods.

Frequently asked questions

  • Can I buy cot mattresses at standard retailers?

    We love the online market, but you'll also be able to find some really great cot mattresses at local UK retailers.

    These include:

    • IKEA cot mattresses
    • Argos cot mattresses
    • John Lewis cot mattresses

    We'd always suggest focusing on certified mattresses or organic materials to ensure the cot bed mattress you choose is the best quality you can afford.

  • Can I buy cot mattresses on Amazon?

    Yes, Amazon is one of the best places to buy cot mattresses.

    Many of the bed-in-a-box mattress brands stick purely to adult mattresses.

    While there are some exceptions, like Eve, you'll find a much better selection of baby mattresses on Amazon.

    Many of the brands we recommend can be purchased online via Amazon.

  • Do I need special bedding for my cot mattress?

    Yes, you'll need to invest in bedding for your baby or young child. 

    You'll need to consider mattress protectors, sheets, duvets, and even pillows and pillow covers.

    Most large-scale baby stores sell these, both at retailers and online.

    It's worth noting that babies under 1 shouldn't use duvets or pillows.

    However, a toddler pillow and duvet can provide extra comfort once your little one is old enough.

  • Can you buy a second-hand cot mattress?

    We would recommend staying away from second-hand cot mattresses.

    It's always better to buy a new cot bed mattress.


    Which? tests have shown that cot mattresses can lose more than 25% of their firmness within a few years.

    A second-hand cot mattress is likely to be too soft or have indentations, which can negatively affect your baby's growth and poses an increased suffocation risk.

    Additionally, second-hand mattresses also pose a few other risks, such as that zips and covers are more likely to break or tear.

    This carries a choking risk. 

    New cot mattresses don't have to be overly expensive. 

    Many of the ones we recommend offer great value for money. 

  • References



Editor & Certified Sleep Therapist

Nicky is an experienced writer and editor with numerous qualifications. As a certified sleep coach, her interests lie in understanding how sleep problems arise from hormonal and environmental issues, particularly as part of stress and anxiety management.

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