Why teens fall asleep late (and what helps)
Teen body clocks shift later. Here is what experts say and what families can do.
By Best Sleep Trackers · Updated October 18, 2026
If your teen is wide awake at 11 PM and impossible to wake at 7, they are not being difficult. In adolescence, the body’s internal clock and sleep drive both change so that sleeping and waking move later. This is biology, not laziness.
What experts recommend
The American Academy of Sleep Medicine asks schools to start middle and high school at 8:30 AM or later, because early starts cut into sleep and affect learning, health and driving safety (AASM position statement, 2017). It also recommends 8–10 hours of sleep for 13–18 year olds (AASM, 2016).
The same statement notes that later start times alone won’t fix every teen sleep problem. Habits matter too.
What can help at home
- Keep a steady wake-up time, including weekends, so the body clock stays anchored. A lie-in of an hour or so is far gentler than sleeping until noon.
- Wind down at the end of the evening. Reduce screens and bright light near bedtime.
- Be careful with late caffeine. Our caffeine cutoff calculator shows how long it lingers.
- Plan backwards. Use the school-night bedtime calculator to work out bedtime from first bell.
If your teen is persistently exhausted, or sleep is affecting mood or school, talk to a doctor.
Sources
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General information only. This tool gives general sleep information and is not a substitute for medical advice. If you're worried about your sleep or your child's, talk to a doctor or pediatrician.