Getting your baby to sleep in a crib comes down to timing, consistency, and a predictable routine. Most babies are developmentally ready for crib sleep training around 4 months of age and 14 pounds, when their bodies begin producing melatonin and regulating their own sleep cycles. Before that point, their ability to distinguish day from night is limited, so structured sleep training won’t be very effective.
When Your Baby Is Ready
Before about 3 months, babies simply don’t have the biological machinery for independent sleep. Their brains haven’t started producing melatonin on a predictable schedule, so expecting them to self-soothe or sleep through the night isn’t realistic. Around 4 months, that changes. At roughly 14 pounds, most babies can also go longer stretches without a feeding, which makes overnight sleep more achievable.
If your baby is currently in a bassinet, the transition to a crib becomes necessary once they can sit independently, push up on their hands and knees, or hit the manufacturer’s height and weight limits for the bassinet. Rolling is the most urgent trigger: once your baby shows any signs of rolling over, they need to move to a crib or portable crib immediately, since a bassinet doesn’t give them enough room to move safely.
If you want to keep your baby in your room but they’ve outgrown the bassinet, a Pack ‘n Play or portable crib works well. The CDC recommends room sharing (not bed sharing) for at least the first 6 months.
Setting Up a Safe Crib
A safe crib has a firm, flat mattress covered by a fitted sheet and nothing else. No blankets, pillows, bumper pads, or stuffed animals. These items increase the risk of suffocation, and babies don’t need them for warmth or comfort, even if it looks bare to you.
Place the crib at least two feet from heating vents, windows, window-blind cords, and lamps, and at least one foot from walls and furniture. Your baby should feel warm but not hot. If their chest is sweaty or hot to the touch, they’re overdressed. A sleep sack is the safest way to keep them warm without loose bedding.
One important safety note on swaddling: if your baby is still being swaddled and begins showing any signs of rolling, stop swaddling immediately. A swaddled baby who rolls onto their stomach can’t use their arms to push up, which creates a suffocation risk. Transition to a sleep sack instead, which keeps their arms free while still providing that cozy, enclosed feeling.
Build a Consistent Bedtime Routine
A bedtime routine signals to your baby’s brain that sleep is coming. Aim for 30 to 45 minutes of the same activities in the same order every night. The specific activities matter less than the consistency, but some are particularly effective at triggering drowsiness.
A warm bath is one of the best tools you have. It works by raising blood circulation to your baby’s hands and feet, which then causes their core body temperature to drop. That cooling pattern mimics what the body does naturally before sleep. After the bath, move into quieter activities: reading a book, playing soft music, gentle rocking, or a few minutes of slow stretching where you softly move their arms and legs. Feed your baby about 15 minutes before placing them in the crib. This settles them physically and emotionally while making them slightly drowsy.
The key is putting your baby down drowsy but still awake. If they fall asleep in your arms and then wake up in the crib, it’s disorienting. They haven’t learned to fall asleep in the crib itself, which means every time they wake between sleep cycles overnight, they’ll need you to recreate that original scenario. Placing them down while still slightly awake teaches them to make the final transition to sleep on their own.
Choosing a Sleep Training Method
There’s no single right approach. The best method is the one you can stick with consistently, because switching back and forth confuses your baby and extends the process.
Full Extinction (Cry It Out)
You complete the bedtime routine, place your baby in the crib awake, say goodnight, and leave the room. If they cry, you don’t go back in. This is the fastest method, but it’s also the hardest emotionally for parents. Babies typically cry less each night and adjust within a few nights to a week.
Graduated Checks (Ferber Method)
This approach adds brief check-ins at increasing intervals. You might check after 3 minutes, then 5, then 10, then every 15 minutes after that. During checks, you can briefly reassure your baby with your voice or a pat, but you don’t pick them up or stay long. The intervals stretch out over several nights, giving your baby progressively more time to settle independently.
Chair Method
You sit in a chair next to the crib while your baby falls asleep, then move the chair farther from the crib every few nights until you’re out of the room entirely. This is the gentlest approach but takes the longest, often two to three weeks. It works well for babies who are very distressed by a parent leaving the room completely.
Handling Night Wakings
Waking during the night is normal, even for sleep-trained babies. The goal isn’t to eliminate all wakings but to help your baby learn to fall back asleep without your intervention. When your baby wakes and fusses, give them a few minutes before responding. Short bursts of fussing or crying often resolve on their own as the baby cycles between sleep stages.
If your baby is under 6 months or under 14 pounds, they may genuinely need a nighttime feed. Hunger cries tend to escalate and don’t settle on their own the way sleep-transition fussing does. Feed them calmly with minimal stimulation (dim lights, no talking, no play) and put them back in the crib awake. The goal is to keep the feeding functional rather than letting it become the sleep association.
What the First Week Looks Like
Nights one through three are the hardest. Your baby may cry for 30 to 60 minutes or more the first night, which is stressful but expected. By the second and third nights, the crying period typically shortens noticeably. Most babies show significant improvement within three to five nights. By the end of the first week, many babies fuss for under 10 minutes before falling asleep.
Naps often take longer to click into place than nighttime sleep. Don’t be surprised if your baby sleeps well at night but resists the crib for naps during the first couple of weeks. The sleep pressure that builds overnight is much stronger than what a baby feels during the day, so nighttime training usually works first.
Common Setbacks and Regressions
Even after your baby is sleeping well in the crib, expect temporary setbacks. Teething, illness, travel, and developmental leaps (like learning to stand) can all disrupt sleep for a few nights. These regressions don’t mean the training failed. Go back to your method, stay consistent, and sleep typically returns to baseline within a few days.
The biggest mistake parents make is abandoning the approach mid-training. If you let your baby cry for 30 minutes and then pick them up, you’ve taught them that 30 minutes of crying gets results. This makes the next attempt harder, not easier. Before you start, make sure you’re ready to follow through for at least a full week. Choose a stretch without travel, visitors, or other disruptions, and make sure both caregivers are on the same page about the plan.
Always place your baby on their back for every sleep, including naps. Once they can roll both ways on their own, it’s safe to let them find their preferred position, but always start them on their back.