Wake windows are typical ranges, not strict rules — some babies consistently run a bit shorter or longer than their age's range. Watch for tired cues alongside the clock.
How to use this
Pick your baby's age range and the time they last woke up (from a nap or overnight sleep), and this tool estimates when to start winding down and the outer edge of when tired cues typically appear, based on the same age-by-age ranges in our full wake windows guide.
Why the range matters more than a single number
Every baby is a little different, and wake tolerance also shifts with how well the previous sleep period went. Treat the window as a planning guide — start paying closer attention to yawning, eye-rubbing, or fussiness as you approach the later end of the range, rather than waiting for the exact minute.