A 4-month-old typically sleeps 12 to 15 hours in a 24-hour period, split between nighttime sleep and daytime naps. That’s a wide range, and where your baby falls depends on their individual development, how well they nap during the day, and whether they’re in the middle of a major sleep shift that happens right around this age.
Nighttime Sleep vs. Daytime Naps
Most of your baby’s sleep happens at night. At 4 months, nighttime sleep typically runs 11 to 12 hours, though that doesn’t mean 11 to 12 hours of uninterrupted rest. Many 4-month-olds still wake one to three times overnight for feeding. Most formula-fed babies can drop night feedings between 2 and 4 months, but breastfed babies often continue needing them longer.
During the day, expect about four hours of total nap time spread across four naps. Individual naps vary in length. Some will be solid stretches of an hour or more, while others might be quick 30-minute catnaps. That’s normal. The last nap of the day is often the shortest, serving as a bridge to bedtime rather than a full sleep cycle.
Wake Windows Between Naps
At 4 months, your baby can handle about 90 to 120 minutes of awake time between sleeps. These wake windows tend to start shorter in the morning and stretch longer as the day goes on. The first wake window after your baby gets up might be closer to 90 minutes, while the last one before bedtime usually needs to reach 110 to 120 minutes so your baby is truly ready for sleep.
Age within the month matters here. A baby at 17 weeks may not tolerate a full 2-hour wake window even at the end of the day, while a baby at 21 weeks will likely find 90 minutes too short even first thing in the morning. If your baby is fussy or fighting naps, adjusting wake windows by 10 to 15 minutes in either direction is a good first step.
The 4-Month Sleep Regression
If your baby was sleeping reasonably well and suddenly isn’t, you’re likely experiencing the 4-month sleep regression. This one is different from later regressions because it reflects a permanent change in how your baby’s brain handles sleep.
In the first few months of life, babies spend most of their sleep time in deep sleep. Around 4 months, their sleep architecture matures to cycle through both light and deep stages, much like adult sleep. The problem is that light sleep phases give babies more opportunities to wake up, and they haven’t yet learned how to drift back to sleep on their own. The result is more frequent night wakings and shorter naps, sometimes for several weeks.
This isn’t a setback. It’s a developmental leap. The regression typically lasts two to six weeks, and sleep gradually improves as your baby adjusts to their new sleep patterns. Keeping nap timing consistent and sticking to a predictable bedtime routine helps them through the transition.
Sleeping Through the Night
Most babies are physically capable of sleeping a 6- to 8-hour stretch by around 3 months, but “capable” and “consistently doing it” are two different things. At 4 months, some babies sleep long stretches while others still wake two or three times. Both are within the range of normal.
Many 4-month-olds still need two to three feedings overnight to comfortably make it through 10 to 12 hours in the crib. If your baby wakes but doesn’t seem hungry, they may just need help settling back into the next sleep cycle, especially if the 4-month regression is in full swing. Nighttime sleep tends to consolidate further between 5 and 6 months for most babies.
A Typical Day at 4 Months
Putting the numbers together, a sample 24-hour cycle for a 4-month-old looks something like this:
- Wake up: 6:00–7:00 a.m.
- First nap: about 90 minutes after waking
- Three more naps: spaced throughout the day with 90- to 120-minute wake windows
- Last nap ends: by about 5:00–5:30 p.m.
- Bedtime: 6:30–8:00 p.m., after a final wake window of about 2 hours
- Night feedings: zero to three, depending on the baby
Total sleep across the day and night lands between 12 and 15 hours for most babies. If your baby is consistently sleeping less than 12 hours total, or seems overtired and cranky throughout the day, adjusting nap timing or moving bedtime earlier by 15 to 30 minutes can make a noticeable difference.
Safe Sleep at This Age
At 4 months, safe sleep guidelines still apply fully. Place your baby on their back for every sleep, including naps. Use a firm, flat mattress in a safety-approved crib with only a fitted sheet. Keep blankets, pillows, bumper pads, and stuffed animals out of the sleep space. If your baby is rolling onto their stomach on their own (which often starts around this age), you don’t need to flip them back, but always start them on their back. Watch for signs of overheating like sweating or a hot chest, and dress your baby in a sleep sack rather than loose blankets.