Most babies are ready to move from a bassinet to a crib somewhere between 3 and 6 months old, though the exact timing depends more on your baby’s physical development than their age. The transition doesn’t need to happen overnight. A gradual approach, starting with daytime naps in the crib, helps most babies adjust within one to two weeks.
Signs Your Baby Is Ready to Move
Your baby’s development is a more reliable signal than the calendar. The clearest sign is rolling. Once a baby can roll over, the shallow sides of a bassinet become a safety hazard because they can roll into the mesh and get stuck, or use the momentum to tilt the entire unit. Current safety standards recommend transitioning to a crib at the first sign of a successful roll.
Even before a full roll, watch for what’s sometimes called “scissoring,” where your baby kicks their legs side to side and repeatedly hits the walls of the bassinet. That’s a sign they need more room to move. If your baby can push up on their hands and knees, they’ve outgrown the bassinet regardless of their weight.
Size matters too. There should be at least 2 inches of clearance between your baby’s head or feet and the ends of the bassinet when they’re fully stretched out. If any part of them is touching the edges, it’s time. Most bassinets have weight limits between 15 and 33 pounds, but the physical milestones above almost always come first.
Room Sharing and Timing
The CDC recommends keeping your baby’s sleep area in the same room where you sleep until at least 6 months of age. This means the crib transition and the room transition don’t have to happen at the same time. If your baby outgrows the bassinet at 4 months, you can place the crib in your bedroom temporarily or use a mini crib in your room while they adjust.
Separating these two changes (new sleep surface and new room) can make each one easier. A baby who has already gotten comfortable sleeping in a crib next to you will have an easier time when that crib eventually moves to the nursery.
A Step-by-Step Approach
The most effective strategy is to start with naps. Even while your baby still sleeps in your room at night, you can offer daytime naps in the crib in the nursery. This gives your baby short, low-pressure practice sessions in the new space. Most babies tolerate one or two crib naps per day within the first few days.
Once naps are going smoothly, move bedtime to the crib. Pick a night when your baby is well-rested and not fighting a cold or teething pain. Keep everything else about the bedtime routine identical: same bath, same feeding, same sounds, same order. The goal is for the crib to be the only thing that’s different.
If you’ve been using a sound machine or swaddle (for babies not yet rolling), bring those with you to the crib. Familiar sensory cues help your baby recognize that it’s still sleep time even though the space has changed. Some parents place a worn T-shirt under the crib sheet for a few hours before sleep so the mattress carries a familiar scent, then remove it before putting the baby down.
Setting Up a Safe Crib
A crib is only as safe as how you set it up. The mattress should be firm and fit snugly inside the frame with no gaps along the edges. The U.S. Consumer Product Safety Commission requires that crib slats be no more than 2 3/8 inches apart, roughly the width of a soda can. If you’re using a secondhand crib, check for missing or cracked slats.
Nothing else goes in the crib. No blankets, pillows, bumper pads, stuffed animals, or positioners. A fitted sheet over the firm mattress is all your baby needs. For warmth, use a sleep sack or wearable blanket instead of loose bedding.
Keep the nursery temperature between 68 and 72 degrees Fahrenheit (20 to 22 Celsius). Babies in cribs can sometimes run warmer or cooler than they did in a bassinet next to your body, so check the back of their neck or chest to gauge whether they’re comfortable. Sweaty skin means it’s too warm. Cool skin to the touch means add a layer.
Mini Crib as an In-Between Step
If space is tight in your bedroom and a full-size crib won’t fit, a mini crib can bridge the gap. It’s larger than a bassinet but small enough to keep in your room, and some children sleep in them comfortably past age 2. Parents who aren’t ready to move the baby to a separate nursery often find this a practical middle ground.
There are trade-offs, though. Mini cribs are narrower, which makes it harder to lower a sleeping baby onto the mattress without bumping the sides and waking them. Babies who like to sleep horizontally or who are tall for their age may outgrow a mini crib by 6 months. The mattresses can also cost more than standard crib mattresses, and most mini cribs don’t convert to a toddler bed, so you’ll eventually need to buy a full-size crib anyway. For most families, going directly to a standard crib is simpler unless bedroom space genuinely doesn’t allow it.
Handling Sleep Disruptions
Expect a few rough nights. It’s normal for a baby who slept well in a bassinet to wake more frequently in a new crib, especially during the first three to five nights. This doesn’t mean the transition is failing. Babies are sensitive to environmental changes, and the crib feels, sounds, and even smells different from what they’re used to.
If the transition coincides with a developmental leap (learning to roll, sit, or crawl), sleep can get particularly choppy. Babies who are excited about a new physical skill sometimes wake at night and want to practice it, then get frustrated because they’re stuck in a crib. This phase typically resolves once the skill is fully mastered, usually within one to two weeks.
The most helpful thing you can do is stay consistent. Keep bedtime at the same time each night and follow the same routine. If your baby wakes, give them a moment to resettle before intervening. Some fussing is normal as they learn to fall asleep in a new space. Track your baby’s sleep for a few nights so you can spot patterns. You might notice, for example, that they wake at the same time each night, which could point to a scheduling issue rather than a problem with the crib itself.
What a Realistic Timeline Looks Like
Every baby adjusts at a different pace, but here’s a rough framework. During the first few days, offer one or two naps in the crib while keeping nighttime sleep in the bassinet. After three to five days of successful crib naps, move bedtime to the crib. The first two or three nights often involve extra wakings. By the end of the first week, most babies are sleeping in the crib with roughly the same pattern they had in the bassinet. By two weeks, the crib is typically old news.
If your baby is intensely resistant after two full weeks of consistent effort, it’s worth looking at other variables: room temperature, noise level, light exposure, or whether the timing overlaps with teething or illness. The crib itself is rarely the long-term problem. It’s usually something else in the environment that needs adjusting.