Baby sleep schedule at 4 months: the 4-month regression, naps and wake windows
Lulla TeamPublished Updated
At 4 months your baby needs 12 to 15 hours of sleep a day. Night sleep grows to 10 to 11 hours — the longest yet — and the daytime settles into 3 to 4 naps. Wake windows widen again, to 90 to 120 minutes, which is 1.5 to 2 hours between sleeps.
This is also the month with a reputation. The 4-month sleep regression is not a step backward and not something you broke: it's your baby's sleep permanently reorganizing into adult-like cycles. Nights often get worse before they get better, and the babies who slept beautifully at 3 months are frequently the ones whose parents notice it most.
See the full wake-window table, from newborn to 2 years→How many naps by age — the full table→When your newborn won't sleep: what to check, in order→Sleep regression by age — the full table→
Does this 4 months schedule match your day?
Lulla times the naps and tells you when the wake window is closing, so you do not have to keep count in your head.
Around 4 months the architecture of sleep changes for good. Your baby stops sleeping in the newborn pattern and starts cycling through distinct sleep stages, with brief surfacings between cycles. If falling asleep currently requires being rocked, fed or held, your baby will ask for exactly that at every one of those surfacings. That's the regression: a developmental step forward with a temporary cost to your nights.
Because the change is permanent, there's nothing to wait out and nothing to fix — but there's something to work with. Keep the wake windows honest at 1.5 to 2 hours, hold the bedtime routine steady, and give your baby chances to go into the crib drowsy but awake when they are calm. No method is the correct one, and you don't have to pick one. Consistency shortens the noisy phase; perfection is not required.
A sample day
The sample day below assumes 4 naps, which is the common shape at this age; on 3-nap days the wake windows stretch toward the 2-hour end. Treat it as a guide rather than a target, especially during a rough regression week.
| Time | What happens |
|---|---|
| 7:00 | Wake-up and first feed |
| 8:30 | Nap 1 · approx. 60 min |
| 11:00 | Nap 2 · approx. 60 min |
| 13:45 | Nap 3 · approx. 45 min |
| 16:15 | Nap 4 · approx. 30 min |
| 19:15 | Bedtime routine and lights out |
A sample day to give you a rough idea — every baby is different. Adjust the times to your child's sleep cues, and talk to your pediatrician about anything that worries you.
Your baby's sleep schedule, by age
One table with everything that matters: total sleep per 24h, wake windows and number of naps, from newborn to age 3. Total sleep follows the National Sleep Foundation recommendations.
Tips for this age
- Hold the safe-sleep rules through the regression: back sleeping, firm flat mattress, and nothing loose in the crib before 12 months. Broken nights tempt improvisation, and this is where it costs the most.
- Darken the room for naps and nights, because melatonin now responds to light and darkness helps your baby link the new sleep cycles.
- Give one low-stakes chance a day to go down drowsy but awake, usually at the first nap, when your baby is least overtired.
- A broken night is hard to reconstruct from memory, and logging sleeps in Lulla shows whether the wake window before the wake-up was too short or too long.
- Do not launch other big changes now — no room move, no dropping a feed — and if the wakings come with fever, inconsolable crying or refusing to feed, call your pediatrician; the regression does not explain everything.
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Common questions
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Keep reading
- Baby tiredness signs: how to read them before the crying starts
- How to build the perfect sleep routine for your baby
- How much do newborns sleep? What's normal by age and when it's too much
Sources
Total sleep per 24 hours follows the National Sleep Foundation's ranges (2015); at 3 months we smooth the step between two of them to 13 to 16 hours. Night sleep, wake windows and the number of naps are Lulla's own reference points, not recommendations from the organizations below. This information is educational and does not replace advice from your pediatrician.
- Hirshkowitz M, Whiton K, Albert SM, Alessi C, Bruni O, DonCarlos L, et al. National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Health. 2015;1(1):40–43.
- American Academy of Pediatrics — Safe Sleep
- NHS — Helping your baby to sleep
- World Health Organization — Guidelines on physical activity, sedentary behaviour and sleep for children under 5 years of age