10 best cot mattresses to help your little one sleep peacefully

When it comes to baby essentials, any parent will tell you that sleep (for both you and your baby) is likely to be top of your wish list during the first few years of parenthood. As such, anything that can help support a healthy bedtime routine for your baby is more than worth the investment. 

In addition to choosing the best baby monitor in your price range, an effective cot mattress is an absolute necessity, ensuring safe and comfortable sleep for your baby when they transition into their own room. As well as making their cot bed a firm and supportive place for your baby to snooze, the best cot mattresses will keep them cosy when it’s cold and cool when it’s hot, while ensuring snuffle-free sleep for children with allergies.

To help you find the best cot mattress for your family’s needs, we’ve tapped into the collective wisdom of Mumsnet parents - the biggest online network of parents in the UK, gathering tried and tested cot mattress recommendations that you can trust. We’ve researched the best cot mattresses on the market today (including mattresses suitable for travel cots) before seeking the latest advice from safe sleep experts and consulting feedback from customers by scrutinising online consumer reviews. 

Looking for more authentic baby gear recommendations? We've got you covered - from the best changing bags to the best breast pumps, we've put together guides to the very best products Mumsnetters love.

Each of the mattresses in this guide has been vetted to ensure they comply with the latest safety standards, are firm and robust and will allow your baby to sleep both safely and comfortably all night long (however long their version of a ‘night’ may be.)

Here are the best cot mattresses for babies.

How we chose our recommendations

Recommendations from real parents

Before we recommend new products, we always ask our trusted Mumsnet users, of which there are more than 8 million each month. That’s a lot of honest, impartial advice.

Expert guidance

We always ensure our information represents the latest recommendations from experts so you can rely on it, and we research each product thoroughly to ensure it follows the latest expert advice and stands up to scrutiny. Here we consulted reputable sources such as Which?, the National Childbirth Trust, The Lullaby Trust and The Royal Hospital for Children in Glasgow.

Consumer feedback

We also scour the internet, leaving no stone unturned to check out real reviews from customers who have bought the products themselves and given both positive and negative feedback.

Celebrated best products

Finally, we check to see which products have won industry awards and received recognition from trusted sources and feed this into our analysis too.

What’s the best type of cot mattress?

There are many types of cot and cot bed mattresses on the market, and they come with many different styles and features. Broadly speaking, here are the five main types of cot mattresses and cot bed mattresses:

• Foam cot mattress – good value for money, and generally lightweight and easy to clean.

• Coil spring cot mattress – open coil springs surrounded by foam and fillings. Tends to be sturdier than a typical foam mattress.

• Pocket spring mattress – springs that are individually wrapped within a cloth sleeve/ Provides good support, but can be pricey.

• Coir cot mattress – manufactured from coconut, latex and wool. Naturally firm and durable.

• Hollow-frame (Purflo) cot mattress – advertised as fully breathable and fully washable. It’s basically a mesh cover stretched over an open frame. Expensive.

Because of the wide variety of cot mattresses currently available, they also come in a wide range of prices from as little as £50 right up to several hundred

How do I choose a cot mattress?

There are many elements to consider when choosing the best cot mattress:

Safety – what’s the safest cot mattress?

The safest cot mattress is one that’s firm with no sagging and that follows the relevant safety laws. Your chosen mattress should fit the cot snugly with no gaps for stray fingers or tiny toes to get trapped.

Truthfully, the look of a baby cot mattress should always be secondary to safety. There’s no getting around it. You might like ribbons and frou frou around your four-poster bed, but where a child sleeps should be kept simple and unfussy.

According to the National Childbirth Trust, British Safety Standards are your friend and you should specifically look for products conforming to them. Horrible as it is to even think of such a thing, these protocols are in place to reduce the number of accidental infant deaths that occur each year due to strangulation or suffocation.

It’s non-negotiable – whatever you buy, look out for the British Standards’ number on swing tickets and product specifications. Which? recommendations on this state: “All mattresses should have the BS 1877-10:2011+A1:2012 number on the labelling or instructions. It's preferable if it also carries BS 7177:1996 and BS EN 16890:2017 + A1:2021.”

Comfort and safe sleeping

‘Firm and flat’ is your mantra when it comes to cot mattresses. Both the centre and the edges should yield slightly and then spring back into shape when you apply pressure to the surface and then release it.

The general rule of thumb for safe sleeping is to always place your baby to sleep on their back – even if you own a breathable crib mattress. Though mattress manufacturers try to consider babies who roll onto their tummies during sleep, virtually all health professionals advise that back sleeping is safest.

Besides suffocation risk, some studies claim that there's an additional danger from babies breathing in more carbon dioxide than oxygen when they are not sleeping on their backs.

The mattress should also fit the cot snugly, with no gaps that your baby’s limbs could get stuck in - any gaps should be no more than 3cm. In addition, the NCT recommends that, when the mattress is in position, there’s a minimum 50cm clearance to the height of the cot to prevent a mobile baby from climbing out.

Many mattresses have breathable covers, which helps to ensure air is flowing freely and that your baby won’t overheat. You can help keep your baby at the right temperature in the night by investing in good quality cotton bedding (baby sleeping bags are the easiest) and ensuring that they are always put on their back to sleep, with her arms free. The Lullaby Trust has good advice on safer sleep and reducing the risk of SIDS (sudden infant death syndrome).

Durability and cleaning

Whether you’re buying a cot mattress, a travel cot mattress or a cot bed mattress, you must make sure that, as a minimum, it’s protected by a waterproof cover to help keep the mattress clean and dry.

The overwhelming testimony of Mumsnetters is that removable, washable zip-on covers are a must. Not only do they allow you to change bedding quickly when accidents occur, but they also prolong the life of your mattress.

This does make them more expensive, however, so if you’re going for a budget model and it doesn’t have a removable cover, it would be well worth buying a separate protective cover for it.

Eco-credentials

There’s no getting around it. Cot mattresses aren’t a buy for life, so lots will end up in landfill. But if you’re fully committed to a green-friendly solution, be careful to read the small print.

While producers such as The Little Green Sheep (see their Twist cot bed mattress above) are admirably transparent, the consumer organisation Which? believes that others play fast and loose with terminology. They say: "Manufacturers can use the terms ‘natural’ and ‘organic’ on products without needing any sort of certification. There are legal requirements for the labelling of organic foods, but not these products.”

Their advice, and ours, is to scrutinise the small print of product specs to ensure that the materials used are truly what they purport to be.

Budget

In a sector where a mattress that broadly fulfils the same function can retail from £20 to over £250, getting what you pay for isn’t necessarily a given.

As a rough guide, foam mattresses are cheap and cheerful and not especially hardwearing, but that might be no bad thing if you’re planning to replace them when those little night accidents come to an end.

Spring-interior mattresses are mini versions of typical adult mattresses and coir and Purflo mattresses are part of a subset of innovative, premium-priced ‘green’ products.

If you’re going for a more premium brand, you might want to think about its longevity. Some mattresses will last a child up to four years of age, such as the Snüz Surface Duo Cot Mattress and the Silver Cross True Fit Superior Cot Bed Mattress that we’ve featured in our round-up, so suddenly a slightly hefty price tag doesn’t seem so bad.

Are secondhand cot mattresses safe?

Secondhand mattresses are best avoided – if only because the links between passed-on mattresses and cot death can neither be confirmed nor refuted. In 2002, a BBC story said that researchers at The Royal Hospital for Children in Glasgow claimed to have found a "significant” link between having a secondhand mattress and a risk of cot death. No causation was established, but it’s worth bearing in mind.

The Lullaby Trust charity, set up to provide expert advice on safer baby sleep and to raise awareness of SIDs, also cautions risk. They say: “If you’re using a secondhand mattress, make sure the mattress you choose was previously completely protected by a waterproof cover, with no rips or tears and is in good condition. The mattress should also still be firm and flat to keep your baby sleeping safely.” For little brothers and sisters moving onto an elder sibling’s mattress, make sure that you also do these checks.

You should also ensure that the mattress fits well, with no gaps between the mattress and the cot, and that the mattress itself is both clean and dry.

What size should a cot mattress be?

What’s important is that your mattress fits your cot snugly, with no gaps anywhere, so measure twice before you order. The standard size for a cot is 120cm x 60cm and 140cm x 70cm for a cot bed. However, some cots are now oval or even round, so if yours isn’t standard you might need to buy the mattress that's designed to go with it or get one custom-made.

What is the best thickness for a cot mattress?

For support, your choice of cot mattress should be no thinner than 8cm. However, a minimum of 10cm is what most experts, including Which?, recommend.

Travel cot mattresses tend to be much thinner - sometimes only around 5cm - but they aren’t intended for regular use. You can replace your travel cot mattress with a thicker version but do check that it fits exactly or is designed specifically for your travel cot.

Never be tempted to add a pillow or blankets to make it feel softer or thicker as this is unsafe. And if you add a thicker mattress, do check that there is still 50cm from the top of the mattress to the top of the side of the cot.

How do I test that my cot mattress is firm enough?

It’s very important that a baby’s mattress is firm. It’s necessary for their skeletal development and also is vital in ensuring their safety while sleeping. Before you buy, search online to check the mattress hasn’t been recalled and that there are no other problems with it. When it arrives, check the following:

• Run your hand across the top surface of the mattress. It should be completely flat, with no bumps, dips or bunched-up bits.

• Press with both hands on various spots on the surface of the mattress. When you remove your hands, there should be no indentation remaining. The mattress should spring back immediately.

• Again, using both hands, press all around the edges, checking that the edges are all strong and stable and that they don’t collapse and can’t be pushed in on themselves. Take special care to check this at the corners.

How long does a cot mattress last?

The average lifespan of a cot mattress is anything between 0 to 48 months. After that point, it's time to move into a big kid's bed. The best practice is to always buy a new cot mattress for each child.

How do I clean a cot mattress?

Your mattress should come with instructions on how to clean it, so read these carefully. Be especially careful not to shrink the cover, if it has one, as this may lead to it compressing the mattress, creating gaps around the outside.

But essentially, if you want to give the mattress a thorough clean, first remove the cover, wash it according to the instructions and ensure it is thoroughly dry. Some mattresses can be washed themselves, but most are wipe-clean at best.

Vacuum all surfaces of the mattress, paying particular attention to anywhere dust might gather. Then wipe it all over with a damp cloth. If you have a spill to deal with, check the label to see if you can use a little laundry detergent too, then leave the mattress standing on one side to dry thoroughly - outside if possible.

Do I need to flip my baby's cot mattress?

It’s a good idea to rotate your baby’s mattress 180 degrees every month or so, just so that it wears evenly. Most mattresses these days don’t flip.

Some have a special surface for sleeping on that might be water-repellent or hypoallergenic, for example, so that needs to stay on top. Others, such as the Snüz Surface Duo Cot Mattress and the Silver Cross True Fit Superior Cot Bed Mattress above, have a ‘baby’ side and a ‘toddler’ side with differing levels of firmness.

Either way, the care instructions that came with the mattress should tell you all you need to know.

Do I need a mattress protector for my cot mattress?

A cot mattress protector is a very good idea, yes. If a nappy overflows in the night and urine soaks into the mattress, this can cause bacteria to develop inside.

Some mattresses come with a removable, washable cover, which is great, but it’s still worth buying a protector to pop on as a spare, in case the cover has to be washed suddenly. A cover will also help to prevent dust mites and other allergens from building up.

What is the best cot mattress/ cot bed mattress in the UK?

From a very wide field, we picked the Tutti Bambini Sprung Cot Mattress as the best mattress for a baby's cot. Available in a larger cot bed size too, this mid-priced mattress has all the features you'd expect to find in a much more expensive mattress. it provides excellent ventillation, is allergy-safe and Mumsnetters love it for cots as well as travel cots.

About the author

Lucy Cotterill is a Mum and Content Writer at Mumsnet, specialising in baby/child and lifestyle product reviews and round-ups. Having written product reviews on her own blog Real Mum Reviews since 2012, Lucy loves to research and explore the pros and cons of products, scrutinising reviews and consumer feedback to help people make confident purchases. 

Originally from a HR background with a degree in Business Studies, Lucy developed a real passion for blogging and writing when her children were young, going on to write for several online publications including US parenting site Pregistry and the Evening Standard. When she’s not manically tapping the keys of her laptop, Lucy loves nothing more than to cosy up with her Kindle and enjoy the latest thriller, or compete in Nintendo Switch rallies with her daughters aged six and 10.

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