Wake Windows by Age: 4 to 36 Months

Wake windows are how long your baby can comfortably stay awake between sleeps. At 4–5 months it’s about 1.5–2.5 hours, at 6–8 months about 2–3 hours, at 9–12 months about 3–4 hours, at 13–18 months about 4–6 hours, and at 18–36 months about 5–6 hours before one afternoon nap.

Getting these right is often the difference between a baby who fights every nap and one who goes down in five minutes. Here is the age-by-age guide I use with families:

4 to 5 months: 1.5 to 2.5 hours awake. 4 to 5 naps, shortening to 3 or 4. Total day sleep around 3.5 to 4.5 hours.

6 to 8 months: 2 to 3 hours awake. 3 naps, often dropping to 2 near 8 months. Total day sleep around 3 to 3.5 hours.

9 to 12 months: 3 to 4 hours awake. 2 naps. Total day sleep around 2.5 to 3 hours.

13 to 18 months: 4 to 6 hours awake. Transitioning from 2 naps to 1, usually somewhere between 14 and 18 months. Total day sleep around 2 to 3 hours.

18 to 36 months: 5 to 6 hours awake. 1 afternoon nap of 1.5 to 2 hours, with a bedtime roughly 5 to 5.5 hours after that nap ends.

Two things I want you to know about these numbers. First, the last wake window of the day — the stretch between the final nap and bedtime — is usually the longest one. If you use the same wake window all day long, bedtime lands too early and you get a 5am waking.

Second, these are starting points, not rules. Watch your baby against the clock, not instead of it. A baby who takes more than 20 minutes to fall asleep is likely undertired and needs a longer window. A baby who fusses, arches, and fights sleep is usually overtired and needs a shorter one. Short 30-minute naps and early morning wakings are both classic signs the windows are off.

If your baby’s schedule looks right on paper but the nights still aren’t working, the schedule usually isn’t the whole story — and that’s worth looking at together.