A 4 month old usually manages wake windows of 1 hour 15 minutes to 2 hours and takes 3 to 4 naps a day, each lasting about 40 minutes to 1 hour 30 minutes. Bedtime usually lands somewhere between 6pm and 8pm. Total sleep across 24 hours is typically 12 to 16 hours.
These numbers come from OBubba's own sleep engine for weeks 17 to 21. They are a guide to start from, not a target your baby has to hit.
At a glance
- Wake windows: 1 hour 15 minutes to 2 hours
- Naps: 3 to 4 naps a day
- Nap length: 40 minutes to 1 hour 30 minutes each
- Total day sleep: 2 hours 30 minutes to 4 hours
- Total sleep in 24 hours: 12 to 16 hours
- Bedtime window: 6pm to 8pm
A sample day
Here is one example of how a day could look, starting with a 7am wake up. It is just one example: babies vary, and so do days.
- 7:00am Wake up for the day, milk feed
- 9:00am Nap 1 (1 hour 15 minutes), after 2 hours awake
- 10:15am Awake
- 12:15pm Nap 2 (1 hour 30 minutes), after 2 hours awake
- 1:45pm Awake
- 3:45pm Nap 3 (45 minutes), after 2 hours awake
- 4:30pm Awake
- 6:30pm Asleep for the night, after 2 hours awake (bedtime routine starts around 6:00pm)
That adds up to 3 hours 30 minutes of day sleep. This example shows a 3 nap day. Many 4 month olds still take 4 naps, especially on days with shorter naps, and that is equally normal.
What's changing at this age
Four months is a big month for sleep. Many babies move from 4 naps towards 3, with wake windows of roughly 1 hour 15 minutes to 2 hours. Some days will be 3 naps, some will be 4, and that back and forth is part of the transition.
This is also when sleep itself matures. Babies begin cycling through lighter and deeper sleep in a more adult-like way, so they surface more fully between cycles. Some families see more night waking and shorter naps for a while. Our calm guide to sleep changes around four months has more detail.
A development wave often lands around here too, with rolling, grabbing and lots of curiosity. Practising new skills during the day can help them feel less exciting at 2am.
Common sleep problems and gentle fixes
More night waking
Keep responses calm and consistent. This is a common phase, and many families find a predictable bedtime routine helps it settle.
Naps of 30 to 45 minutes
Very common now. Offer a few minutes of gentle settling, and if the nap stays short, bring the next sleep slightly earlier.
Not sure if it is 3 or 4 naps
Let the day decide. If naps are long, 3 naps may fit. If naps are short, a fourth catnap stops the evening becoming a struggle.
Early waking
If your baby wakes very early, keep the room dark and the response quiet, and check the last wake window before bed is not too long.
If things feel hard, you are not doing anything wrong. Small, gentle changes made one at a time, and watched for a few days, are usually kinder for everyone than a big overhaul. Look after yourself too: rest when you can, and lean on the people around you.
How OBubba helps
An age chart can only tell you what is typical. OBubba predicts your baby's next nap and bedtime from their own rhythm, not just the numbers on this page, and adjusts through the day as naps run long or short. After around four days of logging, the guidance becomes personal to your baby.
Find out more about nap prediction and how OBubba works as a gentle sleep consultant app in your pocket.
Frequently asked questions
How long should a 4 month old be awake between naps?
Usually 1 hour 15 minutes to 2 hours.
How many naps does a 4 month old need?
Typically 3 to 4 naps, lasting roughly 40 minutes to 1 hour 30 minutes each.
What time should a 4 month old go to bed?
Between 6pm and 8pm suits many babies. On a 4 nap day bedtime tends to land later in that window.
Is the 4 month sleep regression real?
Many families notice changes in sleep around this age as sleep patterns mature. It is common and often a phase, rather than a sign that something is going wrong.
Safety and a gentle reminder
Every sleep, day and night, should follow safer sleep guidance. See The Lullaby Trust safer sleep advice and NHS: helping your baby to sleep. If your baby was born prematurely, use their corrected age when reading these ranges. The ranges are guides, not targets. If you are worried about your baby's sleep, feeding or health, speak to your health visitor or GP.
Keep reading
- Previous month: 3 Month Old Sleep Schedule, Wake Windows and Naps
- Next month: 5 Month Old Sleep Schedule, Wake Windows and Naps
- Every age on one page: wake windows by age
- Sleep changes around four months
- The clocks have just changed? Try our gentle reset after the clocks change
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