Silentnight Healthy Growth Comet Eco Miracoil Single Mattress
The Silentnight Healthy Growth Comet Eco is a medium/firm mattress designed with growing sleepers in mind, available in a UK Single.
- Zoned support as your child grows
- Foam-free with no chemical treatments
- 60-night trial & 5-year guarantee
£219
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Silentnight Healthy Growth Comet Eco Miracoil Mattress
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Mattress details
Mattress
Silentnight Healthy Growth Comet Eco Miracoil Mattress
Size
Firmness
Medium Firm
Construction
Open Coil Spring
Eco-Friendly
Depth (cm)
21
Layers
3
Layer Details
Sleep surface
A luxurious quilted sleep surface that adds an extra touch of comfort. You'll feel a soft, gently cushioned finish rather than sleeping directly on the firmer layers below.
EcoComfort Fibres
Breathable EcoComfort Fibres™ that allow air to move through the comfort layer. In practice this means cooler sleep, useful for children who tend to overheat at night.
Support system
Miracoil® springs offering zoned support, scientifically proven to improve spinal alignment and posture. The zoning gives more resistance where body weight concentrates, keeping the spine in a healthier position.
Layer details from silentnight.co.uk product page, September 2026.
Key benefits
- Made for the beds children actually have: The UK single is the standard size for kids' frames, mid sleepers and bunks, so this mattress drops into the bed your child already owns.
- A slim profile that suits raised frames: At 21cm deep it sits lower than many adult mattresses, which keeps safety rails usable on bunk and cabin beds where a chunkier mattress would ride too high.
- Space left over in a small room: At 3ft wide, a UK single leaves room for a desk, wardrobe and toy storage in bedrooms where every centimetre is contested.
- Works for shared rooms: Two UK singles plus a walkway will fit where one larger bed dominates, which makes this a practical choice for siblings sharing.
- Cheap, easy bedding: Single sheets and duvets are the most widely stocked and least expensive of any UK size, a small saving that repeats every time you replace them.
- Zoned support at a child-friendly size: Miracoil springs give more resistance where weight concentrates, which means proper spinal alignment during the years a back is still developing.
This size suits you if...
You're buying for a child's or teenager's bedroom, a bunk or mid sleeper where the 21cm depth keeps the guard rail effective, or a compact room where a 90cm-wide bed is the sensible ceiling. It also suits a spare room that doubles as an office, or a first flat where the frame came with the tenancy and the mattress didn't.
Consider another size if...
You need something wider than 90cm, since this mattress is only made in a UK single. Couples, adults who spread out and anyone wanting a double or bigger will need a different mattress entirely.
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FAQ's
Will the Silentnight Comet Eco UK single fit a bunk bed?
Yes, and it's a good match. The UK single is the standard bunk bed size at 90 x 190cm, and this mattress is 21cm deep, slimmer than many adult designs. That matters on a raised frame: a thick mattress can lift a child above the guard rail, while this one should keep the rail doing its job. Check your frame's maximum depth to confirm.
What room size do I need for the Comet Eco in a UK single?
We suggest allowing at least 2.1m x 2.8m of floor space, which is our own guidance rather than Silentnight's. That leaves enough clearance to walk around the bed and open drawers. In a child's room competing with a desk and wardrobe, or a loft room with a narrow strip of full-height space, the 90cm width is what makes the fit work.
Is a UK single big enough for an adult on this mattress?
At 90 x 190cm it's the standard one-person size, so a single adult of average build sleeps comfortably. Taller adults should note the 190cm length, and anyone who spreads out may feel confined. Since the medium firm feel can be slightly solid for very lightweight side sleepers, it suits a guest room or first flat better than a restless adult's main bed.
What bedding fits the Silentnight Comet Eco single?
Standard UK single fitted sheets, made for 90 x 190cm mattresses, and a single duvet at 135 x 200cm. Because the mattress is 21cm deep, ordinary single sheets fit without needing the extra-deep versions some adult mattresses require. Single bedding is also the cheapest and most widely stocked of any size, useful when children's bedding needs frequent replacing.
Can I put two of these singles in a guest or shared room?
Often, yes. Two UK singles at 90cm wide each, plus a walkway between them, will fit in rooms where a single larger bed would swallow the floor. It's a common setup for siblings sharing and for guest rooms that host more than one visitor. The zoned Miracoil support works independently on each bed, so one restless sleeper won't disturb the other.