A 5-week-old baby needs roughly 16 hours of total sleep per day, split almost evenly between daytime and nighttime. That sounds like a lot, but it comes in short bursts rather than long stretches, which is why it rarely feels like your baby is sleeping “enough” even when they are.
Total Sleep in 24 Hours
Newborns through the first few months typically sleep 16 to 17 hours per day. At 5 weeks, expect about 8 to 9 hours of that during the day and about 8 hours at night. The catch is that those hours are broken into many small chunks. A 5-week-old may only sleep 1 to 2 hours at a stretch before waking, especially overnight. This is completely normal and driven by biology, not habit.
About half of your baby’s sleep time is spent in active (REM) sleep, which is the lighter, dream-heavy phase. Newborns actually fall asleep into active sleep first, then transition into deeper, quieter sleep after about 20 minutes. That’s why a baby who seemed sound asleep often startles awake shortly after being put down. They hadn’t yet reached deep sleep.
Why They Wake So Often
The main reason a 5-week-old can’t sleep in long blocks is stomach size. By 10 days old, a baby’s stomach is roughly the size of a ping-pong ball, holding about 2 ounces at a time. At 5 weeks it’s a bit larger, but still small enough that it empties quickly. Most babies this age need 8 to 12 feedings every 24 hours, which means waking every 2 to 3 hours around the clock is expected.
Sleeping through the night, usually defined as a 6- to 8-hour stretch without waking, doesn’t happen for most babies until around 3 months of age. If your 5-week-old is waking frequently overnight, that’s on schedule. Nighttime stretches will gradually lengthen as your baby’s stomach grows and they can take in more milk per feeding.
Wake Windows and Naps
Between sleep periods, a 5-week-old can handle about 1 to 2 hours of awake time before needing to sleep again. That awake window includes feeding, diaper changes, and a small amount of alert interaction. It adds up fast. If your baby has been awake for much longer than 2 hours, they’re likely overtired, which can actually make it harder for them to fall asleep and stay asleep.
During the day, expect 6 to 8 naps. Some will be short (30 to 45 minutes), others may stretch to 2 or even 3 hours. There’s no predictable pattern yet at this age. Nap lengths will vary day to day, and that’s normal. You’re not doing anything wrong if the schedule looks different every afternoon.
The 6-Week Growth Spurt
Right around 5 to 6 weeks, most babies hit a noticeable growth spurt. This typically lasts 2 to 3 days, sometimes up to a week. During this stretch your baby will likely wake more often, seem hungrier than usual, and need extra feedings. It can feel like sleep has gotten worse just when you thought things were settling in.
This timing also coincides with what pediatric sleep researchers call “the peak of fussiness.” By 6 weeks, babies are growing out of their drowsy newborn state and starting to notice the world around them. All those new sights, sounds, and sensations are overstimulating, which leads to more fussiness and, paradoxically, more difficulty sleeping. This phase is temporary. Fussiness typically peaks around 6 weeks and gradually improves from there.
What Safe Sleep Looks Like
For every sleep period, whether it’s a 20-minute nap or a 3-hour stretch at night, the safest setup stays the same. Place your baby on their back on a firm, flat surface like a safety-approved crib or bassinet mattress with only a fitted sheet. Nothing else belongs in the sleep space: no blankets, pillows, stuffed animals, or bumper pads.
Keep the crib or bassinet in the same room where you sleep for at least the first 6 months. Room-sharing (not bed-sharing) makes nighttime feedings easier and significantly reduces sleep-related risks. This applies to all sleep, including daytime naps when possible.
Signs Sleep Is on Track
At 5 weeks, you’re not looking for a schedule. You’re looking for a rough total. If your baby is getting somewhere in the range of 14 to 17 hours over a full 24-hour period, gaining weight appropriately, having regular wet and dirty diapers, and having periods of calm alertness when awake, their sleep is likely fine. Some babies naturally sleep a bit more, some a bit less.
The things worth paying attention to are extremes: a baby who seems impossible to wake for feedings, or one who never seems to sleep at all despite being clearly exhausted. Those patterns are worth mentioning at your next pediatric visit. For the vast majority of 5-week-olds, the “problem” isn’t that something is wrong. It’s that newborn sleep simply doesn’t look like adult sleep yet, and it won’t for a few more months.