Buying a child's bed is one of those jobs that looks simple until you start. How old is old enough for a proper bed? Is a single too big for a three year old? Do you need a safety rail, and for how long? And will whatever you buy still work in four years when they have grown half a foot?
We make kids beds in the UK and get asked these questions constantly. Here is the full answer, broken down by age, with the safety points that genuinely matter.
When to Move a Child Out of a Cot
Most UK children move from a cot to a bed between 18 months and 3 and a half years. There is no single right age, and rushing it rarely helps.
Move them when you see these signs:
- They are climbing out of the cot, which makes the cot the more dangerous option
- They are close to the cot's height limit, usually around 90cm tall
- They are out of nappies at night and need to get to the toilet
- A new baby needs the cot, though try to move them a few weeks before the baby arrives rather than the same week
Signs it is too early:
- They are still sleeping well and not climbing
- They are under 18 months
- There is already a lot of change happening, like starting nursery or moving house
A child who moves too early often starts getting out of bed repeatedly at night. There is no prize for going first.
Bed Sizes for Children by Age
UK bed sizes are standard, so this is simpler than it looks.
| Age | Recommended size | Dimensions |
|---|---|---|
| 18 months to 3 years | Toddler bed or small single | 70 x 140cm / 75 x 190cm |
| 3 to 6 years | Single | 90 x 190cm |
| 6 to 11 years | Single | 90 x 190cm |
| 11 to 16 years | Single or small double | 90 or 120 x 190cm |
| 16+ | Small double or double | 120 or 135 x 190cm |
The practical advice: skip the toddler bed if you can. A toddler bed fits a child for about two years, then you buy again. A standard single at 90 x 190cm works from age three right through to adulthood, which makes it the better buy for most families.
A single is not too big for a small child. The space does not bother them, and a safety rail handles the edge.
Our kids beds come in single, small double, double, king and super king, so you can size up as they grow.
UK Safety Rules You Should Know
This is the part that matters most, and the part most guides skip over.
Fire safety regulations
All beds and mattresses sold in the UK must comply with the Furniture and Furnishings (Fire Safety) Regulations 1988. This applies to upholstered beds and mattresses just as much as sofas.
Check for a permanent label confirming compliance. Every bed we make is built to meet these regulations. If you are buying from a marketplace seller rather than a UK manufacturer, check this before anything else, because non compliant imported furniture does turn up.
Bed height
Lower is better for young children. A lower base means a shorter fall if they roll out, and it means they can get in and out without help, which matters at night.
Avoid tall divan bases with deep mattresses for under fives. The combined height can be more than the child can manage.
Safety rails
A safety rail stops a child rolling out while they get used to not having cot sides.
- Use one from the move out of the cot until roughly age 4 to 5
- Fit it to the open side if the bed is against a wall
- Use rails on both sides if the bed stands free
- Leave a gap at the foot so they can still get out
- Check there is no gap between the rail and the mattress a limb could fit through
Most children stop needing a rail once they have gone several months without rolling against it.
Bunk beds and raised beds
UK guidance says no child under 6 should sleep on a top bunk. This is not a soft recommendation, it reflects fall injury data. Also check that guard rails on a top bunk sit at least 16cm above the mattress surface.
Mattress fit
The mattress must fit the bed frame with no gap. A gap at the side is an entrapment risk for small children. Buy the mattress and the bed in the same size, and if you are reusing an old mattress, measure it rather than assuming.
Choosing a Mattress for a Child
Children need different things from adults.
Firmness. Go medium firm. Children are light, so they do not compress a mattress much, but their spines are still developing and a soft sagging surface gives no support. Very firm is unnecessary.
Thickness. Keep it under 20cm for younger children. A deep mattress raises the sleeping surface, which makes the bed harder to climb into and reduces the effective height of any safety rail.
Protection. A waterproof mattress protector is not optional for under sevens. Accidents happen and a mattress without a protector does not recover from them.
Replacement. Children's mattresses wear faster relative to their size because kids jump on them. Expect to replace roughly every 7 years, or sooner if there is a visible dip.
Our mattress range covers single through super king, and the Superb Orthopaedic works well for older children who want firmer support.
Storage: The Thing Parents Underestimate
Children's rooms are usually the smallest in a UK house and hold the most stuff. Toys, clothes they have grown out of, school things, sports kit.
Putting the storage in the bed solves most of it.
Drawer beds. Storage at child height means they can actually tidy up without help, which matters more than it sounds. Two drawers on the open side works best if the bed sits against a wall. Our divan beds come in single with drawer options.
Ottoman beds. A gas lift ottoman bed gives one large compartment for bulky things like sleeping bags, boxed games and out of season clothes. Adults should operate the lift rather than children, so this suits storage you access occasionally rather than daily.
Ottoman boxes. An ottoman storage box at the foot of the bed doubles as seating and holds toys, using floor space that is usually dead anyway.
Bed Ideas by Age
Toddler, 18 months to 3
Low single bed, safety rail on the open side, waterproof protector, mattress under 20cm. Keep the room simple, since too much stimulation near bedtime works against you.
Primary school, 4 to 10
Single with drawer storage. This is the age where a bed earns its keep by holding toys and clothes. A sturdy upholstered headboard is worth having, since children sit up in bed to read.
Teenager, 11 to 16
Single or small double, firmer mattress, proper storage. Teenagers want the room to feel less like a child's room, so a plain upholstered bed in a neutral fabric ages better than anything themed.
Buying a Bed That Lasts
A child's bed gets more abuse than an adult's. Jumping, bouncing, sitting on the edge, friends piling on.
What to look for:
- Solid hardwood frame rather than particle board
- Reinforced centre support on singles and above
- Upholstered rather than hard edges on the headboard, since heads hit them
- Removable or wipeable fabric where possible
- A size they will not outgrow in two years
Everything we build uses solid hardwood from sustainable sources and is handcrafted in the UK, which is a different proposition to flat pack particle board.
Ready to Choose?
Every Bonanza Sleep bed is handmade in the UK and complies with UK fire safety regulations. You can customise the size, fabric, colour, storage type and headboard, so a bed can suit a six year old's room and still work when they are sixteen.
Delivery is free across the UK by a two person team to the room of your choice, with optional assembly. Klarna and Clearpay are both available if you would rather spread the cost.
Not sure which size suits your child's room? Message us on WhatsApp at +44 7529 903256 with the room measurements and your child's age, and we will tell you what fits.
Browse kids beds or order fabric swatches to check colours before you commit.
Frequently Asked Questions
What age should a child move from a cot to a bed?
Most UK children move between 18 months and three and a half years. The strongest signal is climbing out of the cot, since at that point the cot becomes the more dangerous option. Other signs include approaching the cot's height limit around 90cm, or being dry at night and needing the toilet. If they are sleeping well and not climbing, there is no benefit to rushing.
What size bed should I buy for a child?
A standard UK single at 90 x 190cm suits children from around age three right through to adulthood, which makes it the most sensible buy for most families. Toddler beds fit for roughly two years before you have to buy again. A single is not too large for a small child, and a safety rail handles the open edge while they adjust.
Do children's beds need to meet UK fire safety regulations?
Yes. All beds and mattresses sold in the UK must comply with the Furniture and Furnishings (Fire Safety) Regulations 1988, and compliant products carry a permanent label. This applies to upholstered beds and mattresses equally. Check the label before buying, particularly from marketplace sellers, since non compliant imported furniture does appear on UK listings.
How long does a child need a safety rail?
Usually from the move out of the cot until around age four or five. Fit the rail to the open side if the bed is against a wall, or both sides if it stands free, and leave a gap at the foot so they can still get out. Check there is no gap between the rail and the mattress. Most children stop needing one after several months without rolling into it.
What firmness mattress is best for a child?
Medium firm. Children are light and do not compress a mattress much, so a soft surface gives their developing spine no real support, while a very firm one is unnecessary. Keep thickness under 20cm for younger children, since a deep mattress raises the bed height and reduces the effective height of a safety rail.
At what age can a child sleep on a top bunk?
UK guidance says no child under six should use a top bunk, and this reflects fall injury data rather than general caution. If you are using bunk beds, check that the guard rails sit at least 16cm above the mattress surface, and make sure the ladder is securely fixed rather than hooked on.
Should a child's bed have storage?
It is one of the most useful things you can buy, since children's rooms are usually the smallest in a UK home and hold the most clutter. Drawer beds work best for everyday items because storage sits at child height and they can tidy up themselves. Ottoman bases suit bulkier seasonal items, though an adult should operate the gas lift rather than the child.
How often should I replace a child's mattress?
Roughly every seven years, or sooner if you can see a dip or the mattress has had repeated accidents. Children's mattresses wear faster relative to their size because kids jump on them. Use a waterproof protector from day one for under sevens, since a mattress without one rarely recovers from an accident.
Can a child use a double bed?
There is nothing unsafe about it as long as the mattress fits the frame with no gaps and the bed height suits them. The practical issues are floor space and cost. A double takes 135cm of width, which leaves very little room in a typical UK children's bedroom. Most families find a single works better until the teenage years.
What should I look for in a durable children's bed?
A solid hardwood frame rather than particle board, reinforced centre support, and upholstered rather than hard headboard edges since children sit up against them. Children's beds take far more impact than adult beds from jumping and friends piling on. Buying a size they will not outgrow within two years also saves replacing it early.
