29 September 2025 · Roshni Mahtani Cheung
Cofounder, Little Rei · Mother of one
Is My Baby Getting Enough Sleep?
Almost every parent asks this at some point, usually right after they've downloaded an app, added up the day and found a number lower than the one in an article they read. The total matters much less than most sources suggest, and the published ranges are wide because babies really do differ, not because nobody has measured properly.
How much sleep does a baby need by age?
These are the 24-hour ranges, day and night added together, that children's sleep experts agree on. Treat them as what's typical, not as a target to hit.
| Age | Total sleep | Naps | Longest stretch |
|---|---|---|---|
| 0-3 months | 14-17 hours | 4-6, irregular | 2-4 hours |
| 4-6 months | 12-16 hours | 3, settling into a pattern | 5-8 hours |
| 6-9 months | 12-15 hours | 2–3 | 6-10 hours |
| 9-12 months | 12-15 hours | 2 | 8-11 hours |
| 1-2 years | 11-14 hours | 1–2 | 9-12 hours |
| 3-5 years | 10-13 hours | 0–1 | 10-12 hours |
Look at how wide those ranges are. At six months, a baby who sleeps twelve hours and one who sleeps fifteen are both completely normal, even though the gap between them is about a fifth of the day. If your baby is regularly outside the range either way, talk to your doctor, but being at the bottom of it isn't a problem to fix.
Why the total is a poor measure on its own
Two babies with the same daily total can be in very different situations, so the number doesn't tell you much when you look it up at midnight.
- Nobody counts accurately. The totals parents write down often differ from what a device measures by an hour or more either way, because you can't see from outside the room exactly when a nap starts and ends.
- Sleep doesn't come in even amounts. A baby can have a low total on Tuesday, a high one on Wednesday, and average out fine over the week. Judge by one day and almost every baby looks short of sleep.
- Night waking isn't the same as sleep loss. A baby who wakes four times and resettles in two minutes each time has lost eight minutes. A baby who wakes twice and is up for forty minutes has lost far more.
- Growth spurts, teeth, illness and new skills all change the number for a while. Judge over two weeks, not one night.
Elsewhere on sleep
The number gave me something to fail at
For a while I logged all of it, every nap and every waking, in an app. I thought that if I could see the number, I'd know whether we had a real problem, but all the number gave me was something to fail at. Most days Shan slept less than the chart said she should, and every time I opened the app it reminded me. She was feeding well and gaining weight. She was alert between naps and perfectly happy in the daytime. Everything that mattered was fine, and I couldn't see any of it because her total was a couple of hours short of a printed average.
I deleted the app. Of everything I tried that year, that helped fastest.
The signs that tell you
A baby getting enough sleep, over a normal week, mostly looks like this:
- Wakes on their own more often than not, and doesn't always need waking.
- Is alert and sociable for most of the time awake, and gets grizzly near the end of it, not the start.
- Feeds well and is gaining weight along their own curve.
- Settles for naps without a long fight most days.
- Is recognisably themselves by mid-morning, not still bleary an hour after waking.
Signs that she isn't getting enough, which need acting on even if the total looks fine on paper:
- Fighting every nap, then falling asleep instantly in the car or pram: a classic sign of overtiredness.
- Waking after exactly one sleep cycle, repeatedly, and not resettling.
- Early-morning waking that has crept earlier over weeks, not days.
- Sudden clinginess or a shorter fuse with no other explanation.
- Falling asleep during feeds well past the newborn weeks.
If you want one number to work with, use the awake window, which is how long a baby can comfortably stay up between sleeps, not the daily total. It's something you can change. Keeping her up twenty minutes too long is often why bedtime suddenly gets hard for no reason anyone can see. I'm not sure it's the most common cause for everyone, but it was ours.
| Age | Awake window |
|---|---|
| 0-6 weeks | 45-60 minutes |
| 2-3 months | 1-1.5 hours |
| 4-6 months | 1.5-2.5 hours |
| 6-9 months | 2-3 hours |
| 9-12 months | 3-4 hours |
| 12-18 months | 4-6 hours |
Watch the baby and not the clock. These are starting points, and a baby who's happy and calm at the top of the range doesn't need to be put down because a number says so.
Most sleep questions are really a need for reassurance, and there's nothing wrong with that, because reassurance is what you need at four in the morning. A few patterns need a professional, not an internet search: snoring, mouth-breathing or pauses in breathing during sleep; a baby who's often hard to wake; weight gain that has stalled; or sleep that has suddenly got much worse and stayed that way for more than a couple of weeks with no obvious cause. If you feel something is off, trust that feeling. It's right more often than people think.
This guide is general information, written to help you understand a topic and ask better questions. It is not medical advice and does not replace your own doctor, midwife or paediatrician. Anything that worries you about your baby belongs with them.