Wake windows are the ideal amount of time your baby should be awake between naps and before bedtime. If babies have too much awake time, they will be overtired, and if a baby doesn’t have enough awake time for their age, they will be undertired.
Both of these can result in short naps, but in slightly different ways. An overtired baby will be harder to settle, and will have trouble connecting sleep cycles because they’ll have increased cortisol and adrenaline. On the flip side, undertired babies haven’t built up enough sleep drive to have long stretches of sleep.
To give you an idea of what your baby’s wake windows might look like, here are wake windows by age:
- Newborn: 45-60 mins
- Three months: 1.5 hr
- Four months: 1hr 45 mins to 2 hrs
- Five months: 2 hrs to 2 hrs 25 mins
- Six months: 2.5 hrs
- Seven months: 2 hrs 45 mins to 3 hrs
- Eight months: 3 hrs to 3hr 15 mins
- Nine months: 3 hrs 15 mins to 3.5 hrs
- 10-12 months: 3.5 hrs to 3 hrs 45 mins
- 13-18 months (two naps): 3.5-4 hrs
- 13-18 months (one nap): 4.5-5 hrs
- 18-24 months: 5-6 hrs
- 24 months (elimination of nap): 5-6 hrs
So, what are the signs that these wake windows need adjusting?
1. Fighting bedtime or nap time
Sometimes we see a baby fight bedtime when they are overtired as well as when they are undertired. It can be challenging to figure out which one it is, so you can start by asking yourself the following:
- ‘Is my baby in a good mood before I lie them down?’ A good mood usually means undertired, whereas grumpy and fussing can mean overtired.
- ‘Is my baby crying while they are fighting sleep, or are they happily wide awake?’ If your baby is upset and fighting sleep, it is likely they are overtired, whereas if they are happily fighting sleep, it’s more likely they are undertired and need an increase in wake time.
- ‘Are my child’s wake windows within the age appropriate range?’ Remember that the wake windows outlined above are just averages, but if you are well under the range for your baby’s age and experiencing your little one fighting that nap or bedtime, you may want to consider increasing them. The same goes for if you are over that age appropriate range - it may be beneficial to try decreasing that wake window slightly.
2. Short naps
Similarly, your baby can have short naps both when they are overtired or undertired. Look at the questions above to determine which it may be, and if you are unsure, try decreasing wake windows by about five to 10 minutes every couple of days and see if that helps. If this does not result in an improvement, try the opposite and very gradually extend those wake windows by about five to 10 minutes every couple of days.
3. Falling asleep during your nap time or bedtime routine
If your baby is falling asleep during their routine, or can’t stay awake during your nap feed or bedtime feed, they are probably too tired. We want to make sure they are alert enough to get a full feed, rather than a snack, and avoid the other sleep disturbances we can see when babies go to bed overtired.
4. False starts at bedtime
A false start is when your child wakes shortly after they’ve gone to sleep for the night. This usually occurs in the first 35-45 minutes of your child being asleep, right when they’re coming in and out of light sleep. False starts can happen if bedtime is too early and so their body treats it like a nap, if your baby relies on a sleep association to fall asleep and get back to sleep, or very commonly if your baby was put to bed in an overtired state. Try reducing wake windows to see if this helps!
5. Early morning wakings
There can be many reasons we see early morning wakings, such as too much daytime sleep and a need for independent sleep skills, but a big component in why we see early morning wakings is a baby being overtired at bedtime. Try to decrease that awake time before bed. Do this in small intervals so it’s not a big jump for them.
If you’re feeling unsure where to start, here’s a final tip: it’s usually better to err on the side of caution, and start at the lower end of an age appropriate wake window to reduce the risk of your little one being overtired.