A children's mattress isn't just a smaller adult one. The depth matters more, the firmness needs to be different, and it'll be replaced because the child outgrew it rather than because it wore out.
Everything here is made in the UK, built for children and teenagers, and arrives vacuum packed and rolled so it comes upstairs easily. Whether you're looking for a kids' mattress, a junior mattress for a first proper bed, or something deeper for a teenager, the range covers every size and depth.
Start with the bed
This decides everything else, and it's the step people skip.
If the bed isMaximum depthA normal bed frame, no guard railsNo limit. Choose on comfortA bunk bed, high sleeper, mid sleeper or cabin bed with rails15–16cmA trundle or pull-outAround 10cm
On any bed with guard rails, depth is a safety figure rather than a preference. Rails are designed to sit a set height above the mattress surface, and a deeper mattress reduces that clearance. Most children's mattresses on the high street are 20cm or more.
The exact maximum is set by the bed manufacturer and stated on each bed's product page. Re-check it whenever you replace a mattress, not just when you buy the bed.
15cm mattresses, for bunks, high sleepers and mid sleepers
Thinner designs that keep children safely below the guard rails while still offering proper support. A well-made 15cm mattress supports a child's weight perfectly well; the extra depth in an adult mattress is there for adult body weight.
ComfortSleep 15
Reflex foam. Lightweight, budget-friendly and supportive. Good for younger children and spare beds, and the lightest in the range, which matters when you're rotating it or getting it onto a top bunk.
MemoryDream 15
Memory foam over a reflex base, with a breathable knit cover. For children who like a softer, hugging feel, and the quietest of the range if someone sleeps on the bunk below.
PocketRest 15
Pocket springs for a bouncier, more traditional feel with premium support. The one for children who run warm, since springs allow more airflow than solid foam.
Guardian Orthopaedic 15
Firm and supportive, for a growing child who needs more spinal support than the others give.
See the full 15cm bunk bed and high sleeper range
10cm mattresses, for trundles and pull-out beds
TrundleEase 10
Built at 10cm so it clears the frame above when a trundle slides back. A full-size mattress in every other respect; only the depth is reduced. A standard mattress physically won't fit a trundle.
18cm mattresses, for teenagers and older children
For a child ready for a deeper, more adult-style mattress on a bed with no guard rails.
MemoryTeen 18
4cm of memory foam over 14cm of eco foam, medium-firm. Built for a heavier, taller body, and suited to single beds, continental singles, day beds and larger mid sleepers without rails.
Not suitable for a bunk or high sleeper, since 18cm exceeds the guard rail clearance. If your teenager needs more support than 15cm gives and they're on a raised bed, the answer is a different bed rather than a deeper mattress.
Full depth, 20cm and over
For older teenagers, or children who simply want grown-up mattress comfort. These deliver the same performance as an adult mattress in children's sizes.
Best for heavier sleepers, children who've complained of aches, larger bed frames, and anyone wanting a mattress that lasts into adulthood.
Sizes
SizeDimensionsShopCot bed70 x 140cmToddler mattressesShorty75 x 175cmShorty mattressesSmall single75 x 190cmSingle mattressesSingle90 x 190cmSingle mattressesContinental single90 x 200cmSingle mattressesSmall double120 x 190cmSmall double mattressesDouble135 x 190cmDouble mattresses
Single at 90 x 190cm is by far the most common, and it's what most children move into and keep until they leave home.
The two that catch people out: a shorty bed needs a 175cm mattress, not a standard single, and a continental bed needs 200cm rather than 190cm. Both leave a gap or won't fit at all if you get them the wrong way round.
Which mattress for which age?
Age is a rough guide rather than a rule. Weight and sleeping habits matter more, and so does the bed.
RoughlySizeSuggestedOut of a cotCot bed or shortyA firmer option; the child is light and needs support rather than give4 to 8Shorty or singleComfortSleep 15 or Guardian Orthopaedic 156 upwards, on a bunk or high sleeperSingle, 15cm maxMemoryDream 15 or PocketRest 158 to 12, normal bedSingleMemoryDream 15 or PocketRest 1513 upwards, normal bedSingle or continental singleMemoryTeen 18 or deeper
Firmer is the safer choice for a younger child, not softer. A mattress that gives too much lets the hips sink and the spine curve, and it doesn't support a body that's still developing. Too firm creates pressure points at the shoulder and hip, so medium to medium-firm is the sensible middle.
The old advice about very hard mattresses, or putting a board underneath, has long been superseded. Supportive is the aim, not hard.
Choosing by how they sleep
SleepsNeedsIn our rangeOn their sideGive at the hip and shoulder so pressure points aren't loadedMemoryDream 15On their backA medium-firm surface that keeps the spine alignedPocketRest 15 or ComfortSleep 15On their frontFirmer, so the hips don't sink and arch the lower backComfortSleep 15 or Guardian Orthopaedic 15Restlessly, all over the bedSomething that adapts and stays quietMemoryDream 15HotAirflow through the mattressPocketRest 15
Types
TypeFeelBest forReflex foamFirm, supportive, lightweightYounger children, spare beds, tighter budgetsMemory foamContouring, quietRestless sleepers, most childrenPocket sprungTraditional, some bounce, coolerChildren who sleep hotOpen coilFirmer, lighter, more affordableOccasional and guest useOrthopaedicExtra firmWhere firmer support is wantedNatural fillingsBreathable, temperature regulatingSensitive sleepers
Browse by type: pocket sprung, memory foam, open coil, hypoallergenic.
Allergies and accidents
Allergies. If your child has asthma, eczema or a dust mite allergy, what you can wash matters more than the mattress material. Most allergens accumulate in the top few centimetres, so a washable cover and a machine-washable protector do more than anything else.
Accidents. A waterproof mattress protector is the single biggest factor in how long a children's mattress lasts, because most get replaced because of what's happened to them rather than because the foam has worn out. Our Bamboo Mattress Protector is breathable rather than plastic-backed, so it doesn't trap heat the way a standard waterproof protector does.
If it's already happened, our guide to removing urine smell from a mattress covers what actually works.
How long should it last?
Five to seven years for a child, not the seven to ten you'll see quoted elsewhere. That figure is written about adult mattresses, where the limit is the foam or the springs wearing out. Children's mattresses rarely reach that point; they get outgrown or ruined first.
Signs it needs replacing:
- They've outgrown the size. Once there's less than 10cm between the top of their head and the end of the mattress, you've roughly a year left.
- A dip that doesn't recover within a minute or two of getting up.
- Springs you can feel through the surface.
- Staining or a smell that survives a proper clean.
- They say it's uncomfortable. Children rarely complain about a bed unless something's genuinely wrong with it.
More in our guide to how often to change a mattress.
Making it last
- Use a protector from day one.
- Rotate head to toe every three months. Most children's mattresses are single-sided, so rotate rather than flip unless the label says otherwise.
- Vacuum monthly with the upholstery attachment.
- Air it regularly. Pull the bedding back for an hour before making the bed.
- Check the bed base. A broken slat or sagging base ruins a new mattress within months, and it's often the real cause when one seems to have failed early.
- Allow 24 to 48 hours for a rolled mattress to fully expand.
Kids' Mattresses: Common Questions
What is a junior mattress?
A children's mattress for a first proper bed, usually a shorty at 75 x 175cm or a small single at 75 x 190cm. Junior, youth and children's mattress all describe the same thing; there's no separate standard.
What size mattress does a child need?
Most commonly a single at 90 x 190cm. A shorty at 75 x 175cm suits a smaller room, and a small double at 120 x 190cm suits an older child or teenager.
How firm should a children's mattress be?
Medium to medium-firm. Firmer is the safer error, because a mattress that's too soft doesn't support a developing spine.
What depth mattress for a child?
On a normal bed frame, whatever's comfortable. On a bunk bed, high sleeper, mid sleeper or cabin bed with guard rails, 15 or 16cm maximum. On a trundle, around 10cm.
Is memory foam suitable for children?
Yes, on a bed appropriate for their age. Choose a breathable one, since foam retains more heat than sprung.
Foam or sprung for a child?
Foam is quieter, which matters if someone sleeps on the bunk below. Sprung is cooler, which matters for a child who runs warm. Both support a child properly at the same depth.
How long does a children's mattress last?
Five to seven years, though most are replaced because the child has outgrown the size rather than because the mattress has worn out.
What's the best mattress for a child who wets the bed?
Any of them, with a waterproof protector. The protector matters far more than the mattress, and it costs a fraction of replacing one.
Do children need a special mattress?
Not a different construction, but the depth and firmness requirements are different from an adult's, and on any raised bed the depth is a safety limit rather than a preference.
What's the difference between a kids' mattress and an adult one?
Mainly depth and firmness. Ours in the 15cm range are built for guard rail clearance and for a lighter body. The full depth range above 20cm is the same specification as an adult mattress in a child's size.
Read our kids' mattress guide for every size and depth, or the bunk bed mattress guide if you're buying for a raised bed.
Hemel Hempstead, UK
support@millieandjones.co.uk
020 8264 0042
