How much sleep do you need? A guide by age

The "eight hours" figure is an average across healthy adults. The actual range, for any specific person, depends mostly on age. The National Sleep Foundation and American Academy of Sleep Medicine have published consistent ranges based on decades of research; the numbers below are their consensus recommendations.

By age group

• Newborns (0–3 months): 14–17 hours per day, in fragmented chunks
• Infants (4–11 months): 12–15 hours, including naps
• Toddlers (1–2 years): 11–14 hours, including a nap
• Preschoolers (3–5 years): 10–13 hours
• School-age children (6–13 years): 9–11 hours
• Teenagers (14–17 years): 8–10 hours — and they are biologically wired to fall asleep later, which is why early school start times are a public-health issue
• Young adults (18–25 years): 7–9 hours
• Adults (26–64 years): 7–9 hours
• Older adults (65+): 7–8 hours, often with more fragmented sleep

What individual variation looks like

A small percentage of adults — perhaps 1–3% — genuinely thrive on 6 hours. They carry a rare gene variant (DEC2, ADRB1) that supports short sleep without the cognitive cost most of us pay. If you assume you are one of these people, you are almost certainly wrong.

A larger group — maybe 5–10% — needs more than 9 hours to feel well. This is normal long-sleep, not pathology, but if your need has recently increased it's worth a doctor visit (thyroid, depression, sleep apnoea can all cause it).

Signs you're not getting enough

• You need an alarm to wake up most days
• You feel groggy for more than 30 minutes after waking
• You catch yourself dozing during meetings, reading, or driving
• Caffeine is required for normal function, not optional
• Your weekend sleep is more than two hours longer than your weekday sleep — that's "sleep debt" being repaid

What "enough" feels like

You wake up before the alarm most days. Mood is steadier. Hunger and fullness signals are clearer. Workouts feel easier. Decisions feel less effortful. You can hold a long conversation without your mind drifting. You don't need caffeine until mid-morning, if at all.

The bigger point

Sleep is not optional. It is one of the three pillars of every 24-hour day. The hours you spend asleep are not lost — they are the price the body charges for the other 16. Skip the bill long enough, and the body collects with interest.