You’re staring at the monitor. It’s 3:14 AM. Your hair is a nest, and you’re pretty sure you just tried to "shush" a lukewarm cup of coffee. The big question—the one that drives every new parent to the brink of a Google spiral—is basically just: how long should a newborn sleep before I need to worry?
Honestly, the answer is "a lot," but it’s rarely in the way you want it to be. Newborns are tiny biological paradoxes. They sleep for roughly 16 to 18 hours out of every 24, yet somehow, you feel like you haven't closed your eyes in three years. It doesn't make sense. But then again, nothing about those first few weeks really does.
The 24-Hour Blur: Breaking Down the Numbers
Let's get the textbook stuff out of the way first. Most pediatricians, including the experts over at the American Academy of Pediatrics (AAP), suggest that newborns need that 14–17 hour window of shut-eye.
But here is the kicker.
They don't do it all at once. Their tiny stomachs are about the size of a marble (okay, maybe a walnut by the end of week one), which means they have to wake up. They have to eat. Often. If you’re lucky, you get a three-hour stretch. If you’re not, you’re looking at 45-minute "cat naps" followed by an hour of soothing.
👉 See also: Pimple Patches for Cold Sores: Why This Viral Hack Might Be a Huge Mistake
It’s erratic. It's exhausting. It’s completely normal.
Newborns lack a circadian rhythm. They have no idea that the sun is up or that you have a 9:00 AM Zoom call. To them, time is a flat circle consisting entirely of milk and diapers. This "day-night confusion" is why your baby might sleep like a rock from 10:00 AM to 2:00 PM and then decide to throw a rave at midnight.
Why "How Long Should a Newborn Sleep" Varies So Much
Every baby is a literal individual. We talk about them like they're a standardized product, but they aren't.
Some babies are "sleepy babies." You might actually have to wake them up to eat because they’d rather snooze than fuel up, which is a whole different kind of stress. Others are "alert babies" who seem to have a permanent case of FOMO (fear of missing out) from day four.
Dr. Harvey Karp, the guy who basically wrote the book on the "Happiest Baby on the Block" and the 5 S's, points out that the first three months are essentially a "fourth trimester." Your baby isn't really ready for the world yet. Their neurological system is still under construction. This means their sleep isn't "deep" in the way yours is. They spend about 50% of their time in REM (Rapid Eye Movement) sleep.
Why? Because their brains are exploding with growth. REM sleep is where the neural wiring happens. It’s also why they twitch, smile, and make those weird little goat noises in their sleep. They aren't having a nightmare; they’re just downloading "Human 1.0."
The Growth Spurt Factor
Just when you think you’ve figured out how long should a newborn sleep, a growth spurt hits.
Around week two, week three, and week six, the "schedule" (and I use that term loosely) usually goes out the window. Your baby might suddenly want to eat every 45 minutes—a fun little phase called cluster feeding. During these periods, sleep might drop to 12 hours of total disjointed rest, or they might sleep for five hours straight because their body is wiped out from all that growing.
It’s frustrating. It makes you feel like you're failing. You aren't. You're just living through a biological surge.
The Safety Elephant in the Room
We can’t talk about newborn sleep without talking about SIDS (Sudden Infant Death Syndrome). It’s the thing every parent whispers about.
The AAP is very clear on this: The safest way for a baby to sleep is on their back, on a flat, firm surface, with nothing else in the crib. No blankets. No pillows. No cute stuffed elephants. Just the baby and a tight-fitting sheet.
Some parents swear by co-sleeping or "bed-sharing" because it feels like the only way anyone gets any rest. But experts like Dr. James McKenna, who runs the Mother-Baby Behavioral Sleep Laboratory at Notre Dame, emphasize that while "breastsleeping" (a term he coined) happens globally, it requires incredibly strict safety protocols to mitigate risks. Most US-based doctors will tell you to stick to room-sharing instead—keep the bassinet right next to your bed so you can reach out and touch them, but keep the sleeping surfaces separate.
Navigating the "Sleepy" vs. "Lethargic" Distinction
There is a fine line between a baby who is a good sleeper and a baby who is too sleepy.
If your newborn is consistently hitting the 19-hour mark and is difficult to rouse for feedings, that’s a "call the doctor" moment. Dehydration or jaundice can make a baby excessively lethargic. A healthy newborn should wake up, even if they're grumpy about it, and be able to suckle vigorously.
If they’re "floppy" or sleeping through six-plus hours without a feed in those first two weeks, don't wait. Just call. Most pediatric offices have a nurse line for exactly this reason. They’ve heard it all before, and they’d rather tell you "everything is fine" than have you sit at home worrying.
Establishing the "Not-Quite-A-Routine"
Can you train a newborn? No. Don't even try.
Sleep training (like the Ferber method or "Cry It Out") is generally not recommended until a baby is at least 4 to 6 months old. Before that, they literally don't have the emotional or physical capacity to self-soothe. They need you.
However, you can start dropping hints.
- Light and Dark: During the day, keep the house bright. Go for walks. Let the vacuum run. At night, keep things "boring." Low lights. Whispers. No "playtime" during the 2:00 AM diaper change.
- The Swaddle: Most newborns have a "Moro reflex" (that startle reflex where their arms fly out). It wakes them up. A good swaddle mimics the snugness of the womb and keeps those flailing limbs in check.
- Temperature: Overheating is a big risk factor for SIDS. Keep the room between 68 and 72 degrees Fahrenheit. If you’re comfortable in a t-shirt, they’re probably fine in a sleeper and a swaddle.
Real Talk: The Mental Health Side
Let’s be real for a second. When you're asking how long should a newborn sleep, you're often actually asking "When will I feel human again?"
Sleep deprivation is literally used as a form of interrogation. It breaks your brain. It makes you snappy with your partner and makes you cry over a dropped piece of toast.
The "sleep when the baby sleeps" advice is well-meaning but often impossible. Who's going to do the laundry? Who's going to eat? But if you can, try to find a four-hour window where someone else—a partner, a grandparent, a trusted friend—takes the "monitor shift." Research shows that getting at least one four-hour block of uninterrupted sleep can significantly lower the risk of postpartum depression and anxiety.
It’s not selfish to sleep. It’s maintenance.
Common Misconceptions That Keep Parents Up
- "Formula babies sleep longer." Not necessarily. While formula takes longer to digest than breastmilk, there is no guarantee it will result in longer sleep stretches. Plenty of breastfed babies are great sleepers, and plenty of formula-fed babies are night owls.
- "Keep them awake during the day so they sleep at night." This backfires. Big time. An overtired newborn produces cortisol and adrenaline. This makes it harder for them to fall asleep and stay asleep. "Sleep breeds sleep" is a cliché because it’s true.
- "They need a quiet house." Nope. They spent nine months in a womb that was as loud as a vacuum cleaner (blood flow and heartbeats are noisy!). White noise is your best friend.
Actionable Steps for the Next 24 Hours
Stop looking at the clock. Seriously. If you're counting the minutes, you're just increasing your own stress.
Try this instead:
- Track the total, not the timing. Use an app like Huckleberry or just a notepad. At the end of the day, you’ll probably see that even though the stretches were short, the total "how long should a newborn sleep" number is actually close to that 15-hour mark.
- Check the "Hunger Cues." Don't wait for the cry. Rooting, sucking on hands, or fluttering eyelids are early signs. A baby who is fed before they get hysterical will usually drift back to sleep much faster.
- Expose them to natural light. Set the bassinet near a window (safely) or step outside for five minutes in the morning. It helps their internal clock start to distinguish between "active time" and "quiet time."
- Accept the "Witching Hour." Almost every newborn has a period—usually between 5:00 PM and 11:00 PM—where they are just... fussy. They might sleep for 10 minutes and wake up screaming. This isn't a sleep problem; it’s a developmental "witching hour." Just lean into it. Put on a podcast, use a baby carrier, and know that it ends.
The newborn phase is a marathon, but it's one where the finish line keeps moving. Eventually, those 45-minute naps turn into two-hour blocks. The night stretches grow from three hours to five, then six. One morning, you’ll wake up and realize your chest doesn't feel tight with exhaustion. Until then, remember that as long as they are gaining weight and having wet diapers, you are doing it right. The sleep will come. Maybe not tonight, but soon.