Newborns sleep about 16 to 17 hours per day, but they do it in short bursts of just one to two hours at a time. That round-the-clock pattern is one of the biggest surprises for new parents, and it changes significantly over the first year as your baby’s brain matures and their stomach grows large enough to hold more food between feedings.
Newborn Sleep: The First Month
During the first month, babies spend roughly 16 hours a day sleeping, broken into naps that last about three to four hours each, spaced evenly between feedings. There’s no real distinction between day and night yet. Your baby’s internal clock hasn’t developed, so sleep stretches happen just as easily at 2 p.m. as at 2 a.m.
Newborn sleep cycles are also much shorter than adult ones. Adults cycle through light sleep, deep sleep, and dream sleep in roughly 90-minute blocks. Babies move through shorter cycles and spend proportionally less time in deep sleep, which means they wake more easily and more often. This is actually protective: frequent waking helps ensure they feed often enough to support rapid growth.
How Sleep Changes From 4 to 12 Months
After the newborn phase, sleep starts to consolidate into longer nighttime stretches and more predictable daytime naps. From about 4 months to 1 year, most babies nap at least twice a day, once in the morning and once in the early afternoon. Some also need a late-afternoon nap, especially in the earlier part of that range.
By 10 to 12 months, many babies drop the morning nap entirely and settle into one or two longer naps during the day. Total sleep over 24 hours gradually decreases from the 16-to-17-hour newborn range, but daytime and nighttime sleep become more distinct and predictable. Nighttime stretches get longer as your baby’s digestive system matures and they can go longer between feedings.
What “Sleeping Through the Night” Actually Means
One of the most common misconceptions is that a “good sleeper” is a baby who doesn’t wake up at all during the night. That’s not how infant sleep works. According to the American Academy of Pediatrics, a good sleeper at this age is a baby who wakes up frequently but can get themselves back to sleep. It is not a baby who sleeps 10 hours straight without waking.
All babies wake between sleep cycles. The difference is whether they need your help to fall back asleep or can settle on their own. When other parents say their baby is “sleeping through the night,” they often mean the baby is waking but not crying for attention, not that sleep is truly uninterrupted.
Sleep Regressions and Why They Happen
Just when you think you’ve figured out your baby’s rhythm, a sleep regression can throw everything off. These are periods of noticeably worse sleep that typically last two to four weeks. Most babies experience at least one regression in their first year.
Sleep regressions are less about hitting a specific age and more about what your baby is going through at the time. Common triggers include:
- Growth spurts that create extra hunger, leading to additional nighttime feedings
- New milestones like rolling over or pulling up to stand, which babies want to practice even at night
- Separation anxiety, which tends to peak around 9 months
- Illness or discomfort from teething
- Routine changes like travel, a new caregiver, or starting daycare
Regressions feel exhausting, but they’re temporary and usually signal that your baby’s brain is doing something new. Keeping bedtime routines consistent through these stretches helps babies return to their previous sleep patterns once the regression passes.
How Feeding Method Affects Sleep
There’s a persistent belief that formula-fed babies sleep longer than breastfed ones, but the research tells a more nuanced story. A large study of over 4,500 infants found that babies who were exclusively breastfed for at least three months actually had better sleep patterns over the first two years of life. Infants who were not exclusively breastfed had shorter total sleep durations at 3, 6, and 12 months, and were more likely to follow a pattern of consistently shorter nighttime sleep.
This doesn’t mean formula causes poor sleep. Many factors influence infant sleep, and feeding is just one of them. But if you’re breastfeeding and wondering whether switching to formula would help your baby sleep longer, the evidence suggests it probably won’t make the difference you’re hoping for.
Setting Up a Safe Sleep Environment
Because babies sleep so frequently, the environment matters for every nap, not just bedtime. The AAP recommends placing infants on their backs for every sleep in their own dedicated space, whether that’s a crib, bassinet, or portable play yard with a firm, flat mattress and a fitted sheet. No loose blankets, pillows, stuffed animals, or crib bumpers.
Room temperature plays a role too. Overheating increases the risk of sudden infant death, so keep the room between 16 and 20 degrees Celsius (62 to 68 degrees Fahrenheit). A room thermometer takes the guesswork out of it. Dress your baby in one layer more than you’d wear comfortably in the same room, and skip hats indoors since babies release excess heat through their heads.
Avoid letting your baby sleep on a couch, armchair, or in a seating device like a swing or car seat (unless they’re actually in the car). These positions can restrict airflow or allow a baby’s head to fall forward in a way that compromises breathing.
A Quick Look at Sleep by Age
- 0 to 1 month: About 16 to 17 hours total, in 1-to-4-hour stretches around the clock
- 1 to 3 months: Still around 15 to 16 hours, with slightly longer nighttime stretches beginning to emerge
- 4 to 6 months: Two to three naps per day, with nighttime sleep consolidating into longer blocks
- 6 to 9 months: Two to three naps, with many babies capable of longer stretches at night between feedings
- 10 to 12 months: Often down to one or two naps, with the morning nap frequently dropped
Every baby varies. These ranges describe common patterns, not rules. Some babies naturally sleep more or less than average and are perfectly healthy. What matters more than hitting an exact number is whether your baby seems rested, feeds well, and is gaining weight on track. If sleep feels dramatically off from these ranges or your baby seems unusually difficult to rouse, that’s worth bringing up with your pediatrician.