What you see
After you log a wake-up, the Today screen shows the next sleep window. A sample:
13:05–13:35 · High confidence · 150 min after the last wake · Starts in 7 min
- A time range, not a single minute. The range is between 20 and 90 minutes wide, and it narrows as your baby's pattern becomes steadier.
- A confidence level: Low, Medium or High.
- A countdown to the start of the window.
- The reason, so you can see what the estimate rests on.
The same window is on a Home Screen widget. Nap window alerts can send a heads-up a few minutes before each window, and they stay quiet overnight.
How the estimate is made
- Start from the last wake. The anchor is the end of the most recent finished sleep.
- Look up the age range. Nova has a typical wake window for each age band (the table below). For a baby born early it uses the due date, so the band matches their development.
- Read your baby's own recent wake windows. Nova uses the 14 days before that wake. Older history is left out on purpose, because a growing baby's pattern from two months ago says little about today.
- Match the nap of the day. The stretch before the first nap is often shorter than the one before bedtime. Once there are at least three recent windows for the same nap slot, Nova uses those. Until then it uses all recent windows.
- Set aside the odd ones. A gap far too short for the age is usually a resettle, and one far too long usually means a nap was not logged. Neither is counted.
- Blend the two. With no history the estimate is the age range alone. Each logged sleep moves it toward your baby's own typical window. Nova uses the median, so one unusual day does not drag the forecast.
- Add it to the last wake. The result is the middle of the window, with a spread on each side of between 10 and 45 minutes.
The age ranges Nova starts from
These are the starting ranges built into Nova Baby. They are round figures in line with widely published wake-window guidance, and they are wide on purpose because babies differ.
| Age | Typical time awake between sleeps | In minutes |
|---|---|---|
| 0–5 weeks | 45 minutes to 1 hour | 45–60 |
| 6–11 weeks | 1 hour to 1 hour 30 | 60–90 |
| 3–4 months (12–17 weeks) | 1 hour 15 to 2 hours | 75–120 |
| 4–6 months (18–25 weeks) | 1 hour 45 to 2 hours 30 | 105–150 |
| 6–9 months (26–38 weeks) | 2 hours 30 to 3 hours | 150–180 |
| 9–12 months (39–51 weeks) | 3 to 4 hours | 180–240 |
| 12–18 months | 3 hours 30 to 5 hours | 210–300 |
| 18 months and older | 4 hours 30 to 6 hours | 270–360 |
To do the sums yourself, follow the steps in Wake windows by age.
What the confidence level means
- Low. Little or no history yet, so the window comes mostly from age guidance. A brand new log starts here.
- Medium. Nova has some of your baby's own wake windows, or the recent ones vary a lot.
- High. At least eight recent wake windows that agree with each other.
One finished sleep is enough to get a first window. If you import your Huckleberry history, the last 14 days of it count from the start.
When Nova will not predict
- While your baby is asleep. The next window depends on when they wake, so Nova waits for that instead of guessing across a nap in progress.
- Before the first finished sleep. There is no last wake to count from yet.
Is this AI?
People search for baby trackers with AI sleep predictions, and the App Store listing uses that phrase. The sleep window itself comes from a small statistical model that runs on your iPhone. No chatbot is involved, it needs no connection, and this page sets out each step it takes.
The parts of Nova that use a large language model are separate and optional. Ask Nova answers questions about your log, and AI Patterns writes a plain-language read of your baby's whole history. Both are part of Nova Plus and run online.
What it costs
The next sleep window is free, along with logging, import, charts, sharing and widgets. There is no trial clock on it.
Nova Plus is optional and covers Ask Nova and AI Patterns: $7.99 a month or $49.99 a year on the US App Store, with a free trial for new subscribers.
For comparison, Huckleberry's sleep predictions (SweetSpot) are part of its paid Plus plan, according to its US App Store listing on 10 November 2026. See Huckleberry alternatives for the full comparison.
What it cannot do
- It is an estimate, never a rule. If your baby is clearly tired before the window, go with your baby.
- Feeds come first. A predicted window is never a reason to postpone a feed or set aside a worry, least of all in the early weeks. Our guide to newborn sleep covers what to expect, from NHS guidance.
- It only knows what is logged. A missed nap makes the next window less reliable.
- We do not publish an accuracy figure. Each window shows its own confidence and reason instead.
- iPhone only for now, and one baby per app.
- It is not medical advice. Nova Baby is not a medical device. If you are worried about your baby's sleep or health, speak to your health visitor or doctor.
Questions
Which baby tracker has AI sleep predictions?
Nova Baby predicts the next sleep window free on iPhone, with a time range, a confidence level and the reason. Huckleberry offers SweetSpot predictions in its paid Plus plan, and Napper and Baby Daybook also predict naps. Nova's predictions are free, and each one shows how it was made.
Are Nova Baby's sleep predictions free?
Yes. The next sleep window, the countdown, the widget and nap window alerts are free. Nova Plus is an optional subscription for the Ask Nova assistant and AI Patterns.
How long does it take to learn my baby's pattern?
One finished sleep is enough for a first window, based on age. Each logged sleep moves the estimate toward your baby's own pattern, and High confidence needs at least eight recent wake windows that agree with each other.
How accurate is it?
We do not publish an accuracy figure. Every window shows a confidence level and the reason behind it, and the range widens when your baby's recent days have been irregular.
Does it need an account or an internet connection?
No. The sleep window is worked out on your iPhone from the log stored on it. An account is only needed for cloud backup, sharing with a partner, and the Nova Plus features.
Does it work for newborns?
It gives a window from the first logged sleep, starting at 45 to 60 minutes awake for the first five weeks. Newborn sleep is irregular, so expect Low confidence and a wide range early on. In the early weeks feeding needs lead, not the clock.
Does Nova Room change the prediction?
Nova Room logs sleeps with two keys, so the log stays complete when someone else puts the baby down. The prediction itself is the same.
Sources and further reading
We summarise what these sources say and add details of our own app. The organisations below have not endorsed this page.
- Nova Baby - Sleep Tracker: listing, what is free and Nova Plus pricesApp Store (US) · Checked 2026-11-10
- Huckleberry: Baby Tracker: listing, plans and in-app purchasesApp Store (US) · Checked 2026-11-10
- Helping your baby to sleepNHS · Checked 2026-11-01
- Breastfeeding: the first few daysNHS · Checked 2026-11-01
Nova Baby and Nova Room are not medical devices, baby monitors or safety alarms. Sleep windows are estimates, never rules. This page is general information, not medical advice. Huckleberry, Napper and other product names belong to their owners; Nova Baby is independent and not affiliated with them.