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Cot Bed Mattresses

Our cot and cot bed mattresses are not only safe and secure, but comfy and supportive. Let your baby sleep softly - so you can too - with our range of children's mattresses.

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Trustpilot Star rating

Based on 23,078 reviews

Trustpilot Star rating Verified

Cant fault the service - ordered a mattress (sleepeezee wool superb). At time of ordering was told it was 7-10 days for delivery. After 6 days got a message saying it was back in stock and ready for delivery and I was able to select the delivery date. The night before delivery, I received a message with a 2h slot, and the delivery men called 30 minutes before they arrived on the day. I paid for delivery to my chosen room, they did it without breaking a sweat. Mattress is great so far, a huge upgrade from the one we previously had. It was so much cheaper than ones wed been to see in dreams or john lewis and the quality seems just as good. 10/10

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Ana S 20th Jun
Trustpilot Star rating Verified

Prompt delivery and well packaged, delivery slot was as promised and driver was polite.The mattress itself (selecting one can be a mine field) but we was on a budget so decided on a brand we had before, we are both so happy with it considering the price, I got the firm one after suffering from a bad back for some time, I did not expect miracles but wow no more sleeping on the sofa! we both sleep really well and my back pain has stopped in a matter of days. I would definitely recommend this mattress and the supplier.

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Paul 20th Jun
Trustpilot Star rating Verified

Great delivery service. Delivered on correct date and updated thought the process. Happy with service. Mattress is great so far. Had around 3 weeks.

Charlotte Cox - 20th Jun

Help & Buying Guides

How to choose the right cot bed mattress

Babies can sleep for up to 20 hours a day in the first months, so it’s vitally important that a baby mattress is specifically designed to give them the comfort and support that they need. Because babies sleep on their back, a cot mattress needs to be firm but without being too hard.

Babies cannot regulate their body temperature as effectively as an adult, so our baby mattresses are designed to let the air flow pass through easily, keeping baby cooler and more relaxed.

They also need to be super-hygienic, which is why all of our baby mattresses are designed with removable outer covers and wipe-clean, waterproof inner covers. Simply remove the outer cover and pop in the wash, and wipe clean the inner cover if there’s a little night-time accident.

Toddlers can be restless, so our cot bed mattresses are designed to cope with everything from excited jumping up and down to snuggling with Teddy for a dreamy night’s sleep. Cot bed mattresses are usually slightly larger but have the same hygiene features as a baby mattress.

Can you get hypoallergenic baby mattresses?

Very young children can be incredibly sensitive to allergens and chemicals. To give you total peace of mind and to help your child get a great night’s sleep, our cot mattresses are chosen for their purity and hygienic design. Look for an anti-allergy cot mattress that’s free of chemicals that can trigger a reaction. Hypoallergenic cot mattresses also prevent the growth of mould, are anti-bacterial and anti-microbial, lessening the chances of causing an asthma attack or eczema flair-up.

At MattressNextDay, we want everyone to have a great night’s sleep. Our selection of cot mattresses and cot bed mattresses are perfectly suited for our younger customers. Browse our selection and remember that every mattress benefits from free next-day delivery, so your little one could be having sweet dreams all night long!

Do all cots have the same size mattress?

The most common size for a cot bed mattress is 70cm wide by 140cm long. Mattresses of this size should fit most cot beds and fit snuggly into a standard frame with no gaps around the edges that could pinch little fingers.

There are some mattresses that are designed to fit a slightly smaller cot bed at 60cm by 120cm, so it is important to measure your bed carefully to ensure you buy the correct sized cot bed mattress. 

What size cot mattress do I need?

The most popular size for cot mattresses is 120cm x 60cm, while for cot bed mattresses, which are designed for older toddlers, the common dimensions are 140cm x 70cm. These two sizes should fit the majority of both cots and cot beds without being pushed up at the ends or squeezed on the sides. The mattress should lay flat to make sure your little one has a comfortable night’s sleep.

Our top tip: Measure twice, buy once! Remember to measure the interior dimension of your crib, cot, or cot bed (and not the exterior) to ensure your mattress fits perfectly.

Mattress sizeDimensions
Cot Mattress120cm x 60cm
Cot Bed Mattress140cm x 70cm

What type of cot mattresses are available?

Just like adult and kids mattresses, cot bed mattresses are available in both pocket sprung and memory foam designs. The majority of baby mattresses are made from memory foam, but some also incorporate hybrid designs with pocketed springs making up the core of the mattress for a firmer feel.

The benefits of a cot mattress that’s pocket sprung include a more responsive feel, the elimination of movement transference and vibrations, and a cooler, fresher feel thanks to the increased airflow through the springs.

Memory foam mattresses for cots are primarily made from Reflex foam, which is denser and firmer than standard memory foam. They can be a little warmer than pocketed sprung options, so our advice is to look at either a pocket sprung cot mattress or a hybrid option that combines the best of both springs and memory foam.

For more information, read our guide on how to buy a cot bed mattress.

How thick should a cot bed mattress be?

The recommended thickness for a cot bed mattress is at least 10cm. this provides enough padding and support for your baby. Just as in an adult mattress, it should be sufficiently thick enough to transfer the child’s weight effectively if they wriggle or move in the night. The mattress should also be thick enough to ensure that the weight of the child doesn’t cause the mattress to sag.

As the average cot bed mattress will spend around three to five years being used, and taking into account that the child’s weight will more than triple during that time, it will need to be thick and firm enough to support a growing child through all stages of development.

Look out for dual mattresses that have one side designed specifically to be comfortable for babies, and the other that is more robust and suitable for larger toddlers or children.  

Size Imperial Metric
Cot Mattress 3'9" x 1'9" 120cm x 60cm
Cot Bed Mattress 4'6" x 2'3" 140cm x 70cm
Adjustable Small Single 2'6" x 6'6" 75cm x 200cm
Adjustable Single 3' x 6'6" 90cm x 200cm
Adjustable Small Double 4' x 6'6" 120cm x 200cm
Adjustable Double 4'6" x 6'6" 135cm x 200cm
Small Single 2'6" x 6'3" 75cm x 190cm
Single 3' x 6'3" 90cm x 190cm
Small Double 4' x 6'3" 120cm x 190cm
Double 4'6" x 6'3" 135cm x 190cm
King Size 5' x 6'6" 150cm x 200cm
Super King 6' x 6'6" 180cm x 200cm
European Small Single 2'8" x 6'6" 80cm x 200cm
European Single 3' x 6'6" 90cm x 200cm
European Double 4'7" x 6'6" 140cm x 200cm
European King Size 5'3" x 6'6" 160cm x 200cm

All mattress sizes given are approximate and stated sizes refer to the sleeping surface only. Mattresses sizes may vary slightly from their stated dimensions due to manufacturing tolerances, please allow +/- 2 inches (5cm).

Support Best for
 Icon for Memory Foam Memory Foam Body moulding and pressure relieving
 Icon for Natural Fibres Natural Fibres Unrivalled comfort, naturally temperature-regulating
 Icon for Latex Latex Breathable, supportive and eco friendly
 Icon for Cool Gel Memory Foam Cool Gel Memory Foam Active cooling properties, ideal for hot sleepers
 Icon for Soft White Fibres Soft White Fibres Hypoallergenic polyester, soft and durable

Support Best for
 Icon for Pocket Springs Pocket Springs Individual springs for tailored support
 Icon for Foam Foam Conforms to your body's shape, silent (no springs)
 Icon for Open Coil Springs Open Coil Springs Traditional, interlinked springs
 Icon for Pocket Springs Latex Bouncy yet supportive, great for hot sleepers

Firmness Best for
Good for side sleepers, a softer level of support
Good all-rounder for front, side or back sleepers
Medium - Firm
Good for people who change sleeping position
Good for people who sleep on their front or back
Extra Firm
The firmest level of support, also known as orthopaedic

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