How to Get a Baby to Sleep Through the Night.

Babies sleep through the night when two things are true at the same time: they no longer need calories overnight, and they can fall asleep at bedtime without help. Most healthy, full-term babies reach the first around 6 months and the second only when it is deliberately taught. That is why a 9-month-old can weigh 22 pounds and still wake five times — the issue is almost never hunger, it is the sleep-onset association. Fix bedtime and the night follows, typically inside three weeks.

What the age ranges actually look like.

These ranges follow American Academy of Pediatrics total-sleep guidance and typical growth patterns. They are targets, not deadlines — a premature baby, a baby with reflux, or a baby with slow weight gain works to a different timeline set by their pediatrician.

Why babies wake at night.

Every human — adult included — surfaces briefly between sleep cycles, roughly every 45–60 minutes in infancy. Adults roll over and drop back down without ever remembering it. A baby does the same thing if the conditions at that moment match the conditions they fell asleep in. If they fell asleep on the breast, in your arms, or on a bouncing ball, the crib at 1 a.m. is a mismatch, and they wake fully to ask for the original condition back.

That is the whole mechanism. Nearly every other cause parents worry about — teething, a growth spurt, a bad day — is a short-term trigger layered on top of a missing skill. Teething explains two rough nights. It does not explain four months of hourly wakings.

The five-step plan.

1. Fix the daytime schedule first. Age-appropriate wake windows and adequate day sleep come before any night work. An overtired baby produces more cortisol at bedtime and wakes more, not less. See wake windows by age for the numbers.
2. Front-load daytime calories. Full feeds every 3–4 hours during the day, no snacking. Babies who graze all day make up the difference at night by design.
3. Make the room boring. Blackout dark, white noise at 50–55 dB, 68–72°F, and an AAP-compliant sleep space: firm flat surface, back to sleep, nothing loose in the crib.
4. Put your baby down awake. This is the step that actually changes nights. Bedtime routine, then into the crib drowsy but awake, every single night. The method you use to support them through it — checks, chair, pick-up-put-down — is your choice; see sleep training methods compared.
5. Respond the same way every waking. Pick one protocol and keep it identical from 7 p.m. to 6 a.m. Inconsistency teaches persistence: if the fifth cry gets picked up, the baby learns to cry five times.

What a normal timeline looks like.

• Nights 1–2: Longest protest at bedtime. Night wakings mostly unchanged. This is the hardest point and where most families quit.
• Nights 3–4: Bedtime shortens sharply. Wakings often spike briefly — this is an extinction burst and it is a sign the plan is working, not failing.
• Nights 5–7: First long stretch, commonly 6–9 hours.
• Weeks 2–3: Naps consolidate, remaining wakings drop out, 11–12 hour nights stabilize.

The mistakes that stall progress.

• Changing methods mid-week. Three methods in seven nights teaches nothing. One method for fourteen nights teaches everything.
• Leaving bedtime too late. Bedtime after 8 p.m. for a baby under a year is the most common hidden cause of 2 a.m. parties and 5 a.m. wakeups.
• Reintroducing a feed you already dropped. One rough night handled with a feed can rebuild the habit in three.
• Starting during travel, illness, or a move. Wait a week. Start clean.

When to get help.

If you've been consistent for two full weeks without meaningful improvement, if you can't hold a protocol because you and your partner disagree at 2 a.m., or if you're not sure whether the remaining wakings are habit or hunger — that's a plan problem. Start with night weaning if feeds are still in the picture, or book a free 15-minute call and we'll figure out which piece is missing.