How much sleep does the average teenager need per a night?

Varies betweenpeople: We all need 7-8 hours of uninterrupted sleep per night. Teens usually need more as their bodies are growing rapidly - some up to 10 hours. Start with improving sleep - keep the cell phone as far away at night as possible - the electromagnetic fields from it interfere with restfull sleep as do cordless phones. Keep the room dark and cool as well.

Depends on situation: After growth stops a kid can get by on 8 hrs/d but may need more to compensate for a substantial work/workout schedule. Kids in the growth phase should have no less than 9 hrs/night and may need 10+ during growth spurts or added physical demands through workouts. Sleep deficit could lead to headaches/fatigue/poor physical or academic performance/sleep walking and others.