Silentnight Healthy Growth Cosmo Eco Comfort Kids Single Mattress
The Silentnight Healthy Growth Cosmo Eco Comfort is a kids' mattress built around EcoComfort Fibres™, a breathable comfort filling, sitting on an open coil spring system.
- Airflow border helps kids sleep cooler
- Supportive feel, not sink-in soft
- 60-night trial & 5-year guarantee
£239
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Silentnight Healthy Growth Cosmo Eco Comfort Kids Mattress
More available sizes
Mattress details
Mattress
Silentnight Healthy Growth Cosmo Eco Comfort Kids Mattress
Size
Firmness
Medium Firm
Construction
Open Coil Spring
Eco-Friendly
Depth (cm)
23
Layers
3
Layer Details
Sleep surface
A quilted sleep surface fabric on top, which means a soft, cushioned first feel before the firmer support kicks in.
Comfort layer
Breathable EcoComfort Fibres™ with an airflow border. This layer is there to keep air circulating, so your child is less likely to wake up hot and restless.
Support system
An open coil traditional spring system with interconnected springs. The whole surface moves as one, giving a firmer, more uniform feel than pocket springs.
Layer details from silentnight.co.uk product page, September 2026.
Key benefits
- Fits the frames children actually have: At 90 x 190cm it matches standard UK single bed frames, bunks, cabin beds and mid sleepers, so an upgrade rarely means replacing the furniture too.
- Leaves floor space in a busy room: A 3ft-wide bed keeps room free for a desk, wardrobe and toy storage, which matters when the bedroom has to do several jobs at once.
- Breathability where kids need it: The EcoComfort Fibres™ layer and airflow border keep air moving across a single-width surface, so a child who runs warm is less likely to wake overheated.
- Steady support for growing sleepers: The Medium/Firm open coil system gives an even, slightly traditional feel across the full 90cm width, supportive rather than sink-in soft.
- Cheap, easy bedding: Standard single sheets and a 135 x 200cm single duvet fit, and they're the most widely stocked and affordable bedding of any UK size.
This size suits you if...
You're kitting out a child's or teenager's room and want a foam-free, breathable mattress in the standard 90 x 190cm size; your child is moving up from a cot bed or toddler bed to their first full-size single; or you're fitting a bunk, cabin or mid sleeper frame and need a mattress made with children in mind rather than a cut-down adult one.
Consider another size if...
Your child has outgrown a single, or you want a matching mattress in an adult size. This model is made in a UK single only, so for a UK small double or larger you'd need a different mattress altogether.
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FAQ's
What are the dimensions of the Silentnight Healthy Growth Cosmo in a UK single?
It measures 90 x 190cm, which is 3ft x 6ft 3in. That's the standard UK single, so it fits standard single frames, bunk beds and mid sleepers, and takes standard single sheets and duvets without any hunting around for odd sizes.
How much space does a UK single mattress need in a child's bedroom?
We suggest allowing at least 2.1m x 2.8m of floor space. That leaves room to walk round the bed and still fit a wardrobe or desk. In a shared room with two singles, or under a loft slope, measure the walkway and head height before you commit.
Will the Silentnight Healthy Growth Cosmo fit a bunk or mid sleeper frame?
Its 90 x 190cm footprint matches standard UK bunk and mid sleeper frames. The one thing to check is depth: raised frames often set a maximum mattress height so the guard rail stays effective, and this mattress is 23cm deep. Check your frame's stated limit before ordering.
Does the Silentnight Healthy Growth Cosmo come in sizes other than a UK single?
No, the UK single is the only size Silentnight makes it in. That fits its purpose as a children's mattress, but it does mean there's no small double or double for older teens who want more width, so you'd be looking at a different model for those.
Is the UK single version big enough for a teenager?
Yes for most. At 90 x 190cm it's the standard size teenagers sleep on right through to leaving home, and the Medium/Firm feel suits growing bodies. A particularly tall or broad teen may eventually want more width, but this mattress only comes in a UK single.