Sleep Calculator for Teens: How Much They Really Need
If you parent a teen, the 11 p.m.-to-6-a.m. schedule looks like a choice. It's partly biology: adolescent bodies run on a later clock, and punishing it backfires.
The number: 8–10 hours
The National Sleep Foundation puts teens (13–18) at 8–10 hours per night. Most get under 7. The gap shows up as mood swings, worse grades, and higher accident risk — not just grumpiness.
The biological delay
Puberty shifts the circadian rhythm later: teens get sleepy later and wake later naturally. Forcing an early school start fights this directly. Hence the push for later school start times.
A realistic schedule
- Pick a consistent wake time (even weekends, within an hour).
- Work backward in 90-minute cycles to a bedtime that allows 9 hours.
- Cap late screens and caffeine; protect morning light.
Use the calculator together. Let a teen see "9 hours = bedtime X" instead of a parent decree. Ownership beats nagging.
Not medical advice. Persistent late sleep with inability to wake for school may be delayed sleep phase disorder — evaluable by a clinician.