CDC & NHS Guidelines · All Ages · Free
Sleep Calculator by Age —
How Much Sleep Do You Need?
From newborns to seniors, sleep needs change dramatically throughout life. Enter your age for personalized recommendations — based on the latest CDC, NHS, and American Academy of Sleep Medicine guidelines.
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Adults aged 18–64 need 7–9 hours per night. The optimal target is 7.5–8 hours (5 sleep cycles). Sleeping under 7 hours regularly is linked to cognitive decline, weakened immunity, and chronic disease risk.
Teenagers (13–18) need 8–10 hours per night — more than adults because of active brain development. Most teens are severely sleep-deprived due to early school schedules, with national averages near 6–7 hours.
School-age children (6–12) need 9–12 hours. Preschoolers (3–5) need 10–13 hours. Sleep in childhood is critical for growth hormone release, immune development, and emotional regulation.
Complete Reference
Sleep Recommendations — All Age Groups
Official guidelines from the CDC, NHS, and American Academy of Sleep Medicine (AASM).
Sources: CDC Sleep Guidelines · NHS · American Academy of Sleep Medicine (AASM) · American Academy of Pediatrics (AAP)
Visual Guide
Sleep Needs Across the Lifespan
How sleep requirements change from birth to old age — visualized.
Sleep Science
Why Sleep Needs Change with Age
Sleep requirements are not arbitrary — they reflect the brain's changing biological needs at each life stage.
Infancy and Early Childhood (0–5 years): Maximum Sleep
Newborns sleep 14–17 hours because their brains are undergoing explosive development. During sleep, the brain forms new neural pathways at a staggering rate — sleep isn't passive downtime, it's active construction. Growth hormone (GH) is released almost exclusively during deep sleep in young children, making adequate rest essential for physical growth as well.
Infants cycle through sleep stages faster than adults — about every 50 minutes rather than 90 — and spend proportionally more time in REM sleep, which is critical for early language acquisition and sensory processing.
School Age (6–12 years): Sustained High Needs
Children still need 9–12 hours during the school years. This period involves major cognitive development — executive function, attention, memory, and social skills all mature during this time. Sleep deprivation in school-age children is linked to ADHD-like symptoms, poor academic performance, emotional dysregulation, and increased obesity risk.
Unlike adults, sleep-deprived children often become hyperactive rather than lethargic — a misleading presentation that can delay diagnosis.
Adolescence (13–18 years): The Delayed Clock
Teenagers need 8–10 hours, but their biological clocks shift later — a phenomenon called "sleep phase delay." Puberty causes a genuine neurological shift in the circadian rhythm that makes it harder to fall asleep before 11 PM and harder to wake early. This is not laziness; it's biology.
The American Academy of Pediatrics recommends that middle and high schools start no earlier than 8:30 AM. When schools comply, attendance, grades, mood, and sports performance all improve measurably.
Adulthood (18–64 years): 7–9 Hours, Non-Negotiable
Adults require 7–9 hours, with 7.5 hours being the sweet spot for most people — aligning with exactly 5 complete 90-minute sleep cycles. Unlike popular belief, adults cannot truly "adapt" to less sleep. Studies show chronically sleep-restricted adults perform objectively worse on cognitive tests while subjectively rating their performance as fine — they lose the ability to perceive their own impairment.
Older Adults (65+): Changing Architecture, Not Less Need
Older adults need 7–8 hours, but their sleep quality changes significantly. Deep sleep (N3) declines substantially after 60, and REM sleep also diminishes. Sleep becomes more fragmented with frequent nighttime awakenings. The circadian rhythm shifts earlier — evening tiredness comes sooner, and early morning waking is common.
It's a common myth that older adults need less sleep. What changes is their ability to achieve deep sleep efficiently — which means adequate time in bed becomes more important, not less.