Wake windows by age: the complete guide for 0-18 months
Key Takeaways
- Wake windows are the time your baby should be awake between sleep periods — getting them right is key to good naps and nighttime sleep.
- A newborn can only handle 45-90 minutes of awake time, while an 18-month-old can manage 4-6 hours.
- An overtired baby fights sleep harder than an undertired one — catching the right window prevents most bedtime battles.
- The last wake window of the day (before bedtime) is almost always the longest and most important one to get right.
If there is one concept that transforms baby sleep, it is wake windows. Getting the timing right between naps — not too short, not too long — is the foundation of everything else: good naps, easy bedtimes, and fewer night wakings.
What are wake windows?
A wake window is simply the time your baby is awake between one sleep period and the next. It includes everything: feeding, diaper changes, play, and the wind-down routine before the next sleep.
Getting wake windows right matters because your baby's ability to handle awake time is directly tied to their age and development. Too much awake time creates an overtired baby who fights sleep. Too little creates an undertired baby who is not ready to sleep.
Wake window chart by age
These ranges cover the majority of babies. Start in the middle and adjust based on your baby's cues.
0-3 months: 45-90 minutes
Newborns tire incredibly quickly. At this age, most of the day is sleep. Watch for early tired signs (turning away, losing interest in toys) rather than waiting for yawns and eye rubbing, which are late signs.
4-6 months: 1.5-2.5 hours
This is when wake windows start to become more predictable. Most babies at this age have 3 naps, and the last wake window before bed is the longest — often closer to 2.5 hours.
6-9 months: 2-3.5 hours
Many babies transition from 3 naps to 2 during this period. When this happens, wake windows stretch. The first wake window is usually the shortest (around 2-2.5 hours), and the last is the longest (3-3.5 hours).
9-12 months: 2.5-4 hours
Solidly on 2 naps. Wake windows are more consistent but the last one before bedtime is still the longest. If your baby is fighting the second nap, the morning wake window may need to be pushed longer.
12-18 months: 3-5 hours
The transition from 2 naps to 1 usually happens around 14-16 months. Before the transition, expect wake windows of 3-4 hours. After moving to 1 nap, the single wake window before the nap is around 5 hours, and the window after the nap until bedtime is about 4.5-5 hours.
18 months and older: 4-6 hours
On a single nap schedule, your toddler can handle longer stretches. The nap usually falls in the early afternoon, with a 5-6 hour wake window in the morning and a 4.5-5.5 hour window before bed.
Signs your baby is overtired
An overtired baby is harder to get to sleep, not easier. Watch for:
- Fussiness and irritability that seems sudden
- Eye rubbing, ear pulling
- Arching the back
- Becoming hyperactive or "wired" — this is the cortisol kicking in
- Yawning (this is actually a late sign)
- Fighting sleep — taking longer than 20 minutes to fall asleep with protests
If you see these signs, your wake window is probably too long. Try putting your baby down 15 minutes earlier next time.
Signs your baby is undertired
An undertired baby will also have trouble sleeping, but it looks different:
- Happy and content when you try to put them down, but not sleepy
- Playing in the crib instead of settling
- Taking a very short nap (under 30 minutes)
- Calm but awake for a long time after being put down
If this is your baby, push the wake window 15 minutes longer and see if the next nap improves.
How to adjust wake windows
The ranges above are guidelines, not rules. Every baby is different. Here is how to find your baby's sweet spot:
Start in the middle of the range
If your 7-month-old has a range of 2-3.5 hours, start with 2.5-3 hours and observe.
Watch your baby, not the clock
Tired signs are more reliable than exact times. If your baby is showing tired signs 15 minutes before the wake window "should" end, put them down. If they seem happy and alert when the window is "up," give them a few more minutes.
The last wake window is the longest
Almost universally, the wake window before bedtime should be the longest of the day. This ensures enough sleep pressure for a solid night. If you are only going to get one wake window right, make it this one.
Adjust gradually
When you need to extend a wake window (during nap transitions, for example), add 15 minutes at a time over several days. Jumping from 2 hours to 3 hours overnight will likely produce an overtired baby.
Common mistakes
Using the same wake window all day. The first window of the day is almost always the shortest. If you use the same length all day, your baby will be undertired for the first nap and overtired by bedtime.
Relying only on the clock. Wake windows are a framework, not a prescription. A baby who had a terrible nap may need a shorter next window. A baby who slept great may tolerate a longer one.
Ignoring the last wake window. Bedtime is the most important sleep event of the day. If the last wake window is too short, your baby will not have enough sleep pressure to make it through the night.
Tracking wake windows
Keeping mental track of wake windows when you are sleep-deprived is nearly impossible. DodoCare tracks your baby's wake windows automatically and suggests adjustments based on how naps and nights are going. The first 3 days are free.
Frequently Asked Questions
What is a wake window?
A wake window is the total amount of time your baby is awake between one sleep period and the next, including feeding, play, and the bedtime routine. Getting the right wake window prevents overtiredness and undertiredness, both of which cause sleep problems.
How do I know if my baby's wake window is too long?
Signs of an overtired baby include fussiness, rubbing eyes, pulling ears, arching back, becoming hyperactive or wired, yawning, and fighting sleep at nap or bedtime. If your baby takes more than 20 minutes to fall asleep and is upset, the wake window may be too long.
Should all wake windows during the day be the same length?
No. Wake windows typically get longer as the day progresses. The first wake window of the day is usually the shortest, and the last wake window before bedtime is the longest. This is because sleep pressure builds throughout the day.