There are two triggers for moving a child out of a cot, and only one of them is about the calendar. Move when your child reaches 35 inches tall, or when they start climbing out — whichever comes first. That height threshold typically arrives somewhere between 18 and 24 months. But the counterintuitive part, and the thing most parents wish they had known: if your child is not a climber and is perfectly happy in the cot, waiting until nearer three usually goes far more smoothly, because before that most toddlers lack the impulse control to stay put in an unenclosed bed. There is no prize for transitioning early, and a great deal of lost sleep for doing it too soon.
Key takeaways
- 35 inches tall, or climbing out — whichever comes first. Those are the safety triggers.
- Climbing out is not a sign of readiness for a bed. It is a sign the cot has become unsafe, which is different.
- If they are not climbing, waiting closer to three is usually easier — impulse control arrives later than height does.
- Most cot falls happen when the rail is around chest height and a child tries to climb it.
- Toddler beds are designed for children over 15 months and under 50 pounds, per the safety standard.
- Many removable bed rails are not recommended under age two — check the specific product.
- A new sibling arriving is the worst possible reason to rush the move.
General information, not medical advice. Follow the manufacturer’s instructions for your specific cot and bed, and ask your paediatrician about anything particular to your child.
When should you actually make the switch?
Two separate questions get muddled here, and separating them makes the decision much easier.
Question one: is the cot still safe?
This one has answers. The American Academy of Pediatrics and the Consumer Product Safety Commission point to 35 inches in height, or consistent climbing, as the signal to move — usually landing somewhere between 18 and 24 months.
The mechanism behind the height rule is worth understanding. Most falls from a cot happen when a child tries to climb out, and that generally only becomes possible once the rail is around chest level. Below that, the rail is doing its job. Above it, the cot has quietly stopped being a safe enclosure and become a hurdle.
Before you move them, though, check one thing: is the mattress on its lowest setting? A surprising number of climbing problems are solved by dropping it, and that buys months.
Question two: are they ready to stay in a bed?
This one is developmental, and it arrives later than the height does. Before about three, most toddlers do not have the impulse control to remain in an unenclosed sleeping space. A two-year-old in a bed is not being defiant when they get up eleven times — they are a two-year-old with a door they can now reach.
Which gives a clean decision rule:
| Your child | What to do |
|---|---|
| Climbing out, or 35 inches | Move them. Safety beats convenience — the cot is no longer doing its job |
| Under 35 inches, not climbing, happy in the cot | Wait. Closer to three is usually easier for everyone |
| Climbing, but you can still lower the mattress | Lower it first. It may buy you months |
| Potty training and needing night access | A legitimate reason to move earlier — plan for the wandering |
The reason people get this wrong
A new baby arriving is the most common reason families rush the transition, and it is the worst one. You are asking a toddler to give up their bed and gain a sibling in the same fortnight.
If a new baby is coming and your toddler is not yet climbing, the better options are to move them at least six to eight weeks before the birth so the two changes are not linked, or to buy a second sleep space and leave the toddler where they are. A used cot or a bassinet for the newborn costs less than months of disrupted sleep across the whole household.
What kind of bed?
| Option | Suits | The trade-off |
|---|---|---|
| Toddler bed (uses the cot mattress) | Early movers, small rooms | Outgrown in two to three years. Standard is 15 months and up, under 50 lb |
| Convertible cot converted | Anyone who already owns one | Free. Check you still have the conversion rail — people lose them |
| Floor bed (mattress low or on the floor) | Determined climbers, Montessori approach | Nothing to fall from. Requires a genuinely childproofed room |
| Twin or single with rails | Waiting until closer to three | Skips a purchase entirely. Often the sensible choice |
| Bunk beds | Not under six, per standard safety guidance | Top bunks are an older-child product |
The honest view on toddler beds
A toddler bed is a genuinely useful product for a child who has to move at 20 months — it is low, it uses the cot mattress you already own, and it feels less exposed. But if you are waiting until closer to three, you can often skip it altogether and go straight to a twin with a rail, which they will still be using at ten. That is one fewer purchase and one fewer transition.
Bed rails
Useful, but read the product. Many removable bed rails are not recommended for children under two, and fitting matters enormously — a rail must sit flush against the mattress with no gap a child could slip into. Check the specific manufacturer’s age and weight guidance rather than assuming.
The alternative that removes the problem: put the mattress on the floor. There is nothing to fall from.
Childproof the room, not the bed
This is the mental shift that makes the transition work. The moment your child is in an open bed, the room becomes the sleep space — not the bed. So the room is what has to be safe, because at some point they will be in it alone and awake.
- Anchor every piece of furniture — dressers, bookcases, the television. Tip-overs are among the most serious hazards in a child’s bedroom, and a newly mobile toddler will climb.
- Cover outlets and move anything with a cord out of reach.
- Cordless window coverings, or cords tied high and out of reach.
- Window locks or guards.
- Nothing climbable near a window.
- Check what is now reachable from the bed — a lamp, a shelf, a cable. The geometry of the room changes when they can stand on a mattress.
- A baby gate at the doorway or the top of the stairs, if they might wander.
On the door: a gate at the doorway is generally preferred to locking a child in a bedroom, since a lock creates real problems in a fire. A gate contains them while keeping the room accessible.
Do the childproofing before the first night, not after the first incident.
Making the first weeks work
Expect a rough patch. It is normal, and it is usually short if you stay consistent.
- Keep everything else identical. Same bedtime, same routine, same sleeping bag or blanket, same room. Change one variable at a time.
- Let them help. Choosing the bedding gives a toddler a sense of ownership that genuinely helps.
- Do not start the week of anything else — no house move, no new nursery, no new sibling, no holiday.
- Decide in advance what you will do when they get up, and have both parents do the same thing. Calm, boring, minimal talking, straight back to bed. The consistency matters more than the specific method.
- Expect to walk them back many times for the first few nights. This is the developmental gap, not misbehaviour.
- A toddler clock — the kind that changes colour at a set time — works well from around two and a half, once they can grasp the concept.
- Do not go back to the cot after a few bad nights if you moved for safety reasons. If you moved by choice and it is clearly too early, going back is a perfectly reasonable decision.
One reframe worth holding onto: a child getting out of bed repeatedly is not failing at sleep. They are doing exactly what a two-year-old with a new option does. The skill develops. It just develops on its own timetable.
Five things worth knowing
1. Climbing out means the cot is unsafe — not that they are ready for a bed
These get treated as the same signal and they are not. Climbing means the enclosure has failed, so you must act. It says nothing about whether your child can stay in an open bed, which is a separate skill arriving later. Plan for both problems, not one.
2. Lower the mattress before you buy anything
A large share of early climbing is solved by dropping the cot base to its lowest position. It costs nothing and can buy months. Check it before you conclude the cot is finished.
3. Waiting is usually easier than moving early
Impulse control for staying in an unenclosed bed generally arrives nearer three. A contented non-climbing two-year-old moved “because it is time” often produces months of bedtime battles that simply would not have happened six months later. There is no developmental benefit to transitioning early.
4. The new-baby timing trap
Moving a toddler out of their cot in the weeks around a sibling’s arrival stacks two enormous changes together and links them in the child’s mind. Either move them six to eight weeks ahead, or buy a second sleep space. A used cot is cheaper than a season of broken sleep.
5. You may be able to skip the toddler bed entirely
If you wait until closer to three, a twin bed with a rail works immediately and lasts a decade. The toddler bed is a genuinely good product for a child who must move at 20 months — and an unnecessary purchase and an extra transition for one who does not.
Common mistakes
- Moving on age alone. The triggers are 35 inches or climbing, not a birthday.
- Not lowering the cot mattress first. It often solves the problem for months.
- Transitioning for a new sibling. Move six to eight weeks early, or buy a second sleep space.
- Childproofing the bed but not the room. The room is now the sleep space.
- Leaving furniture unanchored. A newly mobile toddler will climb it.
- Changing several things at once — bed, room, routine and nursery in the same week.
- Two parents responding differently to night-time wandering.
- Using a bed rail without checking the age guidance. Many are not recommended under two.
- Assuming a few bad nights means failure. Two weeks is a normal adjustment.
- Buying a toddler bed you do not need, when a twin with a rail would last a decade.
Frequently asked questions
When should a toddler move to a toddler bed?
When they reach 35 inches tall or start consistently climbing out of the cot, whichever comes first — the height threshold usually arrives between 18 and 24 months. But if your child is not climbing and is content in the cot, waiting until closer to three generally goes much more smoothly, because most toddlers lack the impulse control to stay in an unenclosed bed before then. There is no developmental benefit to moving early.
Is my toddler climbing out of the crib a sign they need a bed?
It is a sign the cot has become unsafe, which is not quite the same thing. Most cot falls happen when a child tries to climb out, and that generally only becomes possible once the rail reaches around chest height. So you do need to act — but first check whether the mattress is on its lowest setting, since lowering it solves a lot of early climbing and can buy several months.
What size should a child be to leave the crib?
The commonly cited threshold from the AAP and CPSC is 35 inches in height, typically reached between 18 and 24 months. Toddler beds themselves are designed under the safety standard for children of at least 15 months weighing no more than 50 pounds. Height matters more than age because it determines whether the cot rail still functions as an enclosure or has become something to climb.
Should I move my toddler to a bed before the new baby arrives?
Only if you can do it at least six to eight weeks beforehand, so the two changes are not linked in your toddler’s mind. Otherwise, buy a second sleep space and leave them where they are — a used cot or bassinet for the newborn costs far less than months of disrupted sleep. Moving a toddler out of their bed in the same fortnight a sibling arrives is the most common timing mistake families make.
Do I need a bed rail for a toddler bed?
Most toddler beds have a built-in guard rail and sit low to the ground, which reduces the risk from rolling out. If you are adding a removable rail to a larger bed, check the product’s guidance — many removable bed rails are not recommended for children under two, and fit matters enormously, since a rail must sit flush against the mattress with no gap. A floor bed removes the issue entirely.
How do I stop my toddler getting out of bed?
Decide in advance exactly what you will do, make sure both parents do the same thing, and keep it calm, boring and brief — minimal talking, straight back to bed. Expect to repeat it many times for the first few nights. A toddler clock that changes colour at a set time works well from around two and a half. Consistency matters more than which method you pick.
What should I childproof before moving my toddler to a bed?
Treat the whole room as the sleep space, because it now is. Anchor all furniture including dressers, bookcases and televisions, since tip-overs are a serious hazard and a newly mobile toddler will climb. Cover outlets, use cordless window coverings, fit window locks, remove anything climbable near windows, and check what is newly reachable from the bed. A gate at the doorway is generally preferred to locking the bedroom door.
Can I put my toddler back in the crib if the bed is not working?
If you moved by choice and it is clearly too early, yes — that is a reasonable decision, not a failure, and waiting a few months often makes the second attempt much easier. If you moved because they were climbing out or had outgrown the cot, going back is not safe, and the answer is to work on the room setup and the bedtime response instead.
Do I need a toddler bed, or can I go straight to a twin?
If you are waiting until closer to three, you can usually skip the toddler bed entirely and go straight to a twin with a rail — one fewer purchase and one fewer transition, and they will still be using it at ten. A toddler bed genuinely earns its place for a child who has to move at around 20 months, because it is low, less exposed, and uses the cot mattress you already own.
How long does the toddler bed transition take?
Expect a rough patch of a week or two, which is normal. It goes faster if you change only one variable — same bedtime, same routine, same bedding, same room — and avoid transitioning during any other upheaval like a house move, a new nursery or a holiday. Repeated getting up in the first nights is a developmental gap rather than misbehaviour, and the skill does develop.