Most parents using cry-it-out sleep training see the longest crying on the first night, typically ranging from 45 minutes to 2 hours, though some babies cry for up to 3 hours. By the second or third night, crying usually drops dramatically, often to just a few minutes. There is no single “correct” time limit, but the approach you choose, your baby’s age, and your consistency all shape how long crying lasts and how quickly it resolves.
When Babies Are Ready for Sleep Training
Most babies are ready to begin sleep training around 4 months old. Some do better waiting until the 6-month mark. Before 4 months, babies have short sleep cycles and genuinely need nighttime feedings, so letting a newborn cry it out is not appropriate. By 4 to 6 months, most babies are developmentally capable of longer stretches of sleep and can start learning to fall asleep independently.
Gradual Extinction: Timed Check-Ins
The most widely used structured approach involves putting your baby down awake, then waiting progressively longer intervals before briefly checking in. You don’t pick the baby up or feed them during checks. You simply reassure them for 15 to 60 seconds and leave again. The intervals increase each night:
- Night 1: Wait 3 minutes before the first check, then 5 minutes, then 10 minutes between all remaining checks.
- Night 2: Start at 5 minutes, then 10, then 12 minutes for all remaining checks.
- Night 3: Start at 10 minutes, then 12, then 15 minutes.
- Night 4: Start at 12 minutes, then 15, then 17 minutes.
- Night 5: Start at 15 minutes, then 17, then 20 minutes.
- Night 6: Start at 17 minutes, then 20, then 25 minutes.
- Night 7: Start at 20 minutes, then 25, then 30 minutes.
If your baby falls asleep but wakes later in the night, you restart the intervals for that night’s schedule. These intervals can be adjusted slightly to fit what feels manageable for your family. The key principle is that the gaps between checks grow longer each night, teaching your baby that crying doesn’t result in being picked up or fed, but that you’re still nearby.
Full Extinction: No Check-Ins
Full extinction, sometimes called “cold turkey” cry it out, means putting your baby to bed and not returning until morning (or until a scheduled feeding if your pediatrician recommends one). There is no set maximum time limit in clinical guidelines. The approach relies on complete consistency: responding to crying intermittently can actually make the behavior stronger, because the baby learns that crying long enough eventually works.
This method tends to produce more intense crying on the first night but often resolves faster overall. Many parents report the first night involves 45 minutes to 2 hours of crying, with some babies going up to 3 hours. By the second night, crying frequently drops to under an hour. By the third night, some babies fall asleep in minutes with no crying at all.
What the First Few Nights Typically Look Like
The first night is almost always the hardest. Expect intense, possibly hysterical crying that may last one to three hours. Your baby may stand in the crib, scream, and seem inconsolable. This is normal and does not mean the method isn’t working.
The second night usually brings a noticeable improvement. Most parents report crying drops to somewhere between 20 minutes and an hour. The third night is often the turning point, with many babies falling asleep within 5 to 15 minutes and sleeping through the night for the first time. Some families see full results in 3 nights. Others take a week or two, particularly when the initial crying sessions are shorter (10 to 40 minutes on night one). The pattern holds across both gradual and full extinction: more crying early on generally means faster resolution.
Does Cry It Out Cause Lasting Harm?
This is the question that keeps most parents up at night (sometimes literally). A study published in the Journal of Child Psychology and Psychiatry followed babies whose parents used cry-it-out methods and found no adverse effects on attachment or behavioral development at 18 months. Four separate studies have reported no detrimental impacts on mother-infant pairs. To the contrary, mothers’ mental health, particularly depression, improved after sleep training. Babies continued to develop normal, secure attachments to their parents.
The stress your baby experiences during sleep training is temporary and distinct from the chronic, unresponsive caregiving that does harm attachment. A few hard nights of learning to self-soothe is not the same as neglect.
Setting Up for Success
Before starting any cry-it-out method, your baby’s sleep space needs to be safe enough that you can leave them alone without worry. That means a firm, flat mattress covered only with a fitted sheet. Remove all pillows, blankets, stuffed animals, crib bumpers, and weighted items. These objects are linked to suffocation, entrapment, and SIDS. Your baby should sleep in the same room as you but in their own crib, bassinet, or portable play yard.
Establish a consistent bedtime routine before you start training. A bath, a feeding, a book, then into the crib awake. Putting your baby down drowsy but awake is the foundation of every extinction method, because the goal is for them to learn the skill of falling asleep on their own.
When to Stop and Check on Your Baby
Cry-it-out methods assume your baby is crying because they want to be held or rocked to sleep, not because something is actually wrong. Before each session, rule out the basics: Are they sick? Teething? Is the room too hot or too cold? Is their diaper dirty? Are they hungry? If you’ve confirmed everything is fine, the crying is a protest, not a distress signal.
Stop sleep training immediately if your baby sounds genuinely unwell, is vomiting, has a fever, or seems distressed for reasons beyond wanting you to come back. Illness is not the time to push through. You can always restart once they’ve recovered. Sleep training works best when your baby is healthy, well-fed, and in a predictable routine. Starting during a developmental leap, a move, or a bout of teething will make the process harder on everyone.
Consistency Is the Most Important Factor
The single biggest predictor of whether cry-it-out works is whether you stick with it. Going in and picking your baby up after 45 minutes of crying teaches them that 45 minutes is the price of being held. The next night, they’ll cry for at least that long, and possibly longer. This is called intermittent reinforcement, and it’s the same reason slot machines are so addictive: unpredictable rewards make the behavior stronger.
Pick a method, commit to it for at least a full week, and be consistent every night. If you’re using timed check-ins, keep them brief and boring. Don’t pick the baby up, don’t start a conversation, don’t linger. A quiet “you’re okay, I love you” and then leave. The checks exist to reassure you as much as your baby.