A 4-month-old should sleep 12 to 16 hours in a 24-hour period, including nighttime sleep and naps. That range comes from guidelines endorsed by the American Academy of Pediatrics for infants ages 4 to 12 months. Where your baby falls within that window depends on their individual needs, but most will land close to 14 hours total.
How Nighttime Sleep Looks at 4 Months
By 4 months, most babies are capable of sleeping in stretches of six or seven hours at night. That’s what pediatricians actually mean by “sleeping through the night” at this age, even though it’s far from the eight-hour block adults expect. The rest of nighttime sleep typically happens in shorter chunks broken up by one or two feedings.
If your baby is waking to feed more than twice per night at this age, that pattern may be worth addressing. Most 4-month-olds can go five or more hours between nighttime feedings, so frequent waking could signal a habit rather than genuine hunger. Total nighttime sleep usually adds up to roughly 10 to 12 hours, with brief wake-ups in between.
Daytime Naps and Wake Windows
Expect about four hours of daytime sleep spread across four naps. These naps won’t all be the same length. You’ll likely see a mix of two shorter naps (30 to 60 minutes) and two longer ones (1 to 2 hours). Some days will look nothing like this pattern, and that’s normal at 4 months, when nap schedules are still inconsistent.
The time your baby can comfortably stay awake between naps, often called a “wake window,” runs about 1.25 to 2.5 hours at this age. Cleveland Clinic places the range for 3- to 4-month-olds in that bracket. Going much beyond 2.5 hours tends to push babies into overtired territory, which paradoxically makes it harder for them to fall asleep.
Signs that your baby has been awake too long include sudden fussiness, crying, clinginess, losing interest in toys, or a burst of hyperactive movement. If you’re seeing those cues, the nap window has likely passed, and getting your baby down quickly will prevent a harder battle at bedtime.
The 4-Month Sleep Regression
Four months is one of the most common ages for a sleep regression, and there’s a biological reason for it. Around this time, your baby’s brain is reorganizing the way it cycles through sleep stages. Newborns have only two sleep stages. At 4 months, the brain starts transitioning to a more adult-like pattern with multiple stages of light and deep sleep. That neurological shift can cause frequent wake-ups, shorter naps, and difficulty settling, even in babies who were previously good sleepers.
The good news is that this disruption typically lasts a few days to a few weeks. It’s not a sign that something is wrong. It’s actually a marker of healthy brain development. Sleep often improves on its own once the new patterns stabilize, though some babies need a little help relearning how to connect sleep cycles without fully waking.
Why Circadian Rhythms Matter Now
Your baby’s internal clock is still relatively new. Infants don’t produce meaningful amounts of melatonin, the hormone that signals sleepiness, until around 9 weeks of age. By 4 months, that system is up and running but still developing. This means your baby is biologically ready for a more predictable sleep schedule, but environmental cues play a big role in reinforcing it.
Consistent light exposure during the day and dim, quiet conditions at night help strengthen your baby’s circadian rhythm. A short bedtime routine, even just 10 to 15 minutes of the same sequence each evening, signals to the brain that it’s time to wind down. These habits matter more at 4 months than they did during the newborn phase because your baby’s brain can now respond to them.
What a Typical Day Might Look Like
Putting it all together, a 4-month-old’s day generally follows a rhythm of sleeping, waking for 1.5 to 2.5 hours, then sleeping again. A realistic day might include waking around 7 a.m., taking a morning nap around 8:30 or 9, then cycling through three more naps before a bedtime between 7 and 8 p.m. The nighttime stretch accounts for the bulk of total sleep, with naps filling the remaining four hours or so.
Don’t expect this to look identical every day. At 4 months, schedules shift based on nap length, overnight sleep quality, and whether a regression is in play. Watching your baby’s tired cues is more reliable than watching the clock. If your baby is getting somewhere in the 12- to 16-hour range over 24 hours, seems alert and content during wake windows, and is gaining weight normally, their sleep is on track.