Wake windows for a 9-month-old
A 9-month-old can usually stay awake 2 hr 45 min – 4 hr 15 min between sleeps. Rytmi starts from 3 hr 30 min, then learns your baby’s own rhythm from a few days of logs.
When to put your baby down next
Wake window — usually —
Next nap around — usually —
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At 9 months
| Starting point | Usual range | |
|---|---|---|
| Wake window | 3 hr 30 min | 2 hr 45 min – 4 hr 15 min |
| Next nap after waking at 7:00 AM | 10:30 AM | 9:45 AM – 11:15 AM |
| Time between feeds | 4 hr 30 min | 3 hr 10 min – 5 hr 50 min |
| Bedtime | 8:00 PM | 7:10 PM – 8:50 PM |
What changes at this age
At nine months the window takes its next step: Rytmi starts from 3 hr 30 min, 45 min more than at eight months. For many babies the day now settles around two naps, and the second one tends to move later.
The stretch before bedtime is usually the longest of the day. If bedtime turns into a battle, check how long your baby was awake since the last nap — a few days of logs make the pattern easy to see.
From about 12 months, Rytmi starts from 4 hr 30 min.
Signs the window is closing
Playing more slowly than usual, rubbing their eyes, turning away, fussing for no clear reason — the window is closing, even if the numbers say there is time left. It works the other way as well: an alert, busy baby doesn’t have to fall asleep on schedule.
Where these numbers come from
These are the age-based starting points Rytmi uses until your baby has a history of their own. Once there are enough entries, the app works from your baby instead: their own wake windows, their own bedtime, their own time between feeds.
- They are not medical norms and not a diagnosis
- The middle of the range is a guide, not a target
- Your baby’s own rhythm beats any chart
Read next
Short naps: why they happen and what helps
Wake windows by age
Newborn · 2 months · 3 months · 4 months · 5 months · 6 months · 8 months · 9 months · All ages
Rytmi does the math for you
Log a few naps and feeds, and the app starts showing your baby’s own wake windows instead of averages.
Rytmi is on iPhone for now. The Android app isn’t on Google Play yet.
For iPhone · free · no ads
The ranges on this page are for planning the day and are not medical advice. For questions about your child’s health, sleep and development, talk to your pediatrician.