Most sleep training experts recommend capping any single crying stretch at 60 minutes for naps, with many methods using shorter check-in intervals of 3, 5, and 10 minutes along the way. Nap training is trickier than nighttime training because daytime sleep pressure is weaker, so knowing when to intervene and when to wait makes a real difference in whether it works.
Time Limits by Method
How long you let your baby cry depends on which approach you’re using. The two most common methods handle timing very differently.
Graduated checks (Ferber method): You put your baby down awake, leave the room, then return at increasing intervals to briefly reassure them without picking them up. A typical schedule starts with a check at 3 minutes, then 5 minutes, then 10 minutes, stretching the gaps a little longer each round. You repeat this cycle until the baby falls asleep or until you decide the nap attempt isn’t going to work. Most families set a total limit of 30 to 60 minutes before calling it.
Full extinction (unmodified cry it out): You put the baby down and don’t return until the nap is over or a set time has passed. This is harder emotionally for parents but often produces faster results because check-ins can sometimes restart the crying cycle.
The Crib Hour Rule
One of the most popular frameworks for nap training is the “crib hour.” The idea is simple: your baby stays in the crib for a full 60 minutes from the moment you put them down, regardless of what happens. If they fall asleep after 20 minutes and wake up at the 45-minute mark, they stay in the crib until the 60-minute point. If they never fall asleep at all, you do a cheerful pickup at the 60-minute mark and move on with your day.
The timer starts when the baby goes into the crib, not when the crying begins. So if you put them down at 9:00 and they fall asleep at 9:15, they stay until at least 9:45 (60 minutes from when they fell asleep) or 10:00 (60 minutes from crib time), depending on which version you follow. Some families count from sleep onset, others from placement. Either way, the purpose is the same: giving the baby enough time to learn to connect sleep cycles on their own, which is what turns a 30-minute catnap into a restorative longer nap.
If your baby is screaming the entire 60 minutes with no signs of settling, that’s your signal to end the attempt. Sixty minutes of continuous, escalating crying is the upper boundary, not the goal.
When Nap Training Is Appropriate
Babies aren’t ready for cry-based nap training until around 4 to 6 months of age. Before that point, their sleep cycles are too immature and they may still need daytime feedings that interrupt nap schedules. By 4 months, most babies have developed the neurological ability to self-soothe, which is the entire skill you’re trying to teach.
Nap training also works best when your baby is already somewhat successful with nighttime sleep training. Nighttime sleep is driven by stronger biological sleep pressure, so it’s easier for babies to learn the skill at bedtime first. Trying to start with naps alone often leads to frustration for both of you.
How Much Crying to Expect
The first day is almost always the worst. A 2018 study tracking real-world sleep training found that crying peaked on the first day and resolved within a week. By the end of the second week, most babies have learned the skill and cry little or not at all when placed in the crib for naps.
If you’re not seeing any improvement after a full week, something else may be going on. The nap schedule might be off, the baby might not be tired enough, or there could be a developmental leap disrupting sleep. It’s worth pausing and reassessing rather than pushing through weeks of crying with no progress.
Naps typically take longer to improve than bedtime. It’s normal for nighttime sleep to click within 3 to 4 days while naps lag behind by a week or more. Many families see one nap improve before the others, usually the morning nap, since sleep pressure is highest after a long overnight stretch.
Will Crying Harm Your Baby?
This is the question behind the question for most parents searching this topic. A study supported by the American Academy of Pediatrics directly measured cortisol (the body’s primary stress hormone) in babies who went through sleep training and compared them to babies who didn’t. By the end of training, the sleep-trained babies actually had lower cortisol levels than before. At the one-year follow-up, there was no difference in attachment style or behavioral problems between the two groups.
Short periods of crying in a safe sleep environment, with a responsive caregiver available the rest of the day, are not the same as prolonged neglect. The stress a baby experiences during sleep training is temporary and bounded. What you’re teaching is a skill, and like most skills, the learning process involves some frustration before it clicks.
Practical Tips That Affect How Long They Cry
Several factors directly influence how much crying you’ll deal with during nap training. Getting these right can shorten the process significantly.
- Wake windows: If your baby has been awake too long, they’ll be overtired and fight sleep harder. Too short a wake window and they won’t have enough sleep pressure to fall asleep at all. For a 5-month-old, wake windows are typically around 2 to 2.5 hours.
- Sleep environment: A dark room, white noise, and a consistent pre-nap routine (even a short one, just 5 minutes) all signal to your baby that sleep is coming. These cues reduce the confusion that fuels crying.
- Consistency: Letting your baby cry for 20 minutes, then picking them up and rocking them to sleep, teaches them that 20 minutes of crying earns a rescue. Whatever method you choose, commit to it for at least a full week before evaluating.
- Putting them down awake: The entire point of sleep training is teaching your baby to fall asleep independently. If they’re drowsy or nearly asleep when they hit the crib, they haven’t practiced the skill. Place them in the crib alert and calm.
Some naps will simply fail during training, and that’s expected. If your baby doesn’t sleep after 60 minutes, pick them up, keep them awake until the next nap window, and try again. A skipped nap isn’t a setback. It’s just one attempt that didn’t work. The pattern matters more than any individual nap.