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Free tool

Wake window calculator

Tell us your baby's age and when they woke — we'll tell you roughly when the next sleepy window opens.

Wake windows by age

1 month	35–60 min
2 months	45–75 min
3 months	60–90 min
4 months	75 min – 2 hrs
5 months	1.5–2.5 hrs
6 months	2–2.5 hrs
7 months	2.5–3 hrs
8 months	2.5–3 hrs
9 months	3–3.5 hrs
10 months	3–3.5 hrs
11 months	3.5–4 hrs
12 months	3.5–4 hrs

A wake window is simply how long your baby can happily stay awake between sleeps. Go past it and they get overtired — which makes falling asleep harder, not easier. Watch your baby more than the clock: eye-rubbing, ear-pulling, staring into space and sudden fussiness all mean the window is closing.