How long to let a baby cry during sleep training: the numbers by method and age

"How long do I let my baby cry?" is the question behind every sleep training search, and most answers dodge it. Here are the numbers, by method and by age, and the signs that mean you go in whatever the clock says.

The short answer

The waits are a ceiling on how long you leave crying before a check-in, not a target. If the crying stops or drops to grumbling, you do not go in.

By age

• Under 4 months. You do not let a baby this age cry for sleep training. Respond, soothe, and work on routine and timing. Sleep is not mature enough for a method to teach anything.
• 4 to 5 months. Short waits only, with your pediatrician's OK. Many families start at 2 or 3 minutes and go no higher than 10 for the first week, and keep night feeds.
• 6 to 11 months. The standard chart works. Ferber's book starts at 3 minutes on night 1 and reaches 30 by night 7. See the full chart.
• 12 months and up. Same chart. Toddlers protest louder and for longer at first, because they can stand and because they have more practice getting their way, but they also learn fast once the rules are consistent.

Protest versus distress

This is the part that matters more than the minutes. Protest crying is loud, rhythmic, often on and off, and usually sounds angry. It is the sound of a baby who wants the old way back. Distress is different: a sudden change in pitch, choking, a cough that does not clear, crying that goes up and up without the pauses. Parents recognise the difference within a night or two.

Go in immediately, regardless of the interval, if:

• the cry changes suddenly in pitch or character
• you hear coughing, gagging or vomiting
• your baby is standing and stuck, or a limb is through the bars
• your baby is ill, feverish or clearly in pain
• it has been far longer than usual and something feels wrong

Trusting that instinct is not breaking the method. The method assumes you are listening.

Why the waits get longer

The point of the growing interval is not to toughen anyone up. A check-in at minute 3 reassures a baby who is just starting to protest. The same check-in at minute 3 on night 5 would interrupt a baby who was about to drop off. Lengthening the waits follows the baby's growing skill. If a longer wait clearly makes your baby more frantic rather than calmer, stay at the shorter interval for a few more nights. Ferber was explicit that the chart can be slowed down.

Total crying falls quickly

The number that frightens parents is night 1. In most studies and in most families' logs, total crying roughly halves each of the first few nights, with a bump around night 3 or 4 (the extinction burst), then falls to a few minutes of grumbling by the end of the first week. Log it. Seeing 65 minutes become 40 become 12 is what gets most families through night 3. How to log night wakes shows how to do it in one tap.

If you cannot do the waiting

That is a valid answer, and there are methods for it. The chair method keeps you in the room throughout. Pick up put down has no waiting at all. Bedtime fading reduces crying by fixing timing first. They take longer, and they work. Sleep training methods compared goes through each.

FAQ

How long should you let a baby cry it out?

With the Ferber method, waits start at 3 to 5 minutes and grow to about 30 by the end of the first week, with a brief check-in at each. With full extinction, there are no check-ins until morning or a planned feed. Under 4 months, you do not let a baby cry for sleep training at all.

Is it OK to let a baby cry for 30 minutes?

In the context of sleep training a healthy baby over about 6 months, a 30 minute wait with calm check-ins is within what the research has studied and found safe. It is not OK if the cry sounds like distress, if your baby is ill, or if you are not comfortable with it, in which case a gentler method is the right choice.

What is the difference between protest crying and distress?

Protest is loud, rhythmic, often angry, with pauses. Distress is a sudden change in pitch, choking or gagging, or crying that escalates without breaks. Go in immediately for distress regardless of the timer.

Does letting a baby cry cause harm?

Studies following children up to five years after graduated extinction found no differences in emotional health, behaviour, stress or attachment compared with children who were not sleep trained. Full extinction has been studied less at long follow up, which is one reason many pediatricians suggest the check-in version.

How long do you let a 6 month old cry it out?

A 6 month old is a typical age to start. Follow the chart: 3, 5 and 10 minutes on night 1, growing each night. If you want a gentler start, begin at 2 or 3 minutes and cap at 10 for the first few nights, then lengthen.

Sources

• Ferber, R. Solve Your Child's Sleep Problems, revised edition (2006)
• Price AM et al. Five year follow up of harms and benefits of behavioral infant sleep intervention. Pediatrics, 2012
• Gradisar M et al. Behavioral interventions for infant sleep problems: a randomized controlled trial. Pediatrics, 2016
• Mindell JA et al. Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep, 2006
• Canadian Paediatric Society, Caring for Kids: Healthy sleep for your baby and child