Sleep tendency changes with time awake, circadian timing, naps, light, feeding and many individual factors. Wake-window ranges are planning context, not a diagnostic threshold or proof that a particular factor caused settling difficulty.
Glossary
Sleep pressure
Sleep pressure is the body's building drive to sleep that grows the longer you're awake — the mechanism behind wake windows and tired cues.
Related guides
Wake windows: how long awake between sleeps
A wake window is simply the awake time between sleeps, and it grows slowly as your baby does.
Naps and nap transitions
Your baby's daytime sleep shifts naturally as they grow, and a few gentle signs help you read when a nap is on its way out.
Try the tool: Wake Window Calculator
Related terms
General information, not medical advice. For concerns about your child, talk with your doctor or child-health nurse.