How much sleep do you need by age?

“Get eight hours” is the advice everyone repeats, but it’s only true for part of the population for part of their lives. The amount of sleep your body needs changes dramatically from birth to old age — and even among adults of the same age, the right number varies. Here is a complete, age-by-age breakdown of how much sleep you actually need and why.

The quick reference chart

These ranges follow the consensus recommendations from the National Sleep Foundation and the American Academy of Sleep Medicine. They cover total sleep in a 24-hour period, including naps for younger children.

Ranges are guidelines, not targets to hit exactly. The right number is the one that leaves you alert and steady through the day.

Newborns and infants (0–11 months)

Newborns sleep more than they’re awake, but in short, scattered bursts of two to four hours around the clock, because their circadian rhythm — the internal body clock that ties sleep to the day-night cycle — hasn’t developed yet. Their sleep is also heavy in active sleep, the infant precursor to REM, which supports the explosive brain development of the first months.

By around three to six months, a more adult-like pattern emerges and longer night stretches appear. Total sleep need stays very high because nearly every system in the body is still being built.

Toddlers and preschoolers (1–5 years)

Daytime naps gradually consolidate: most toddlers drop to a single afternoon nap, and many children give up napping entirely somewhere between ages three and five. Consistent bedtimes matter enormously at this age — an overtired toddler is famously harder to settle, not easier, because sleep deprivation raises stress hormones that fight against sleep.

School-age children (6–13 years)

Children in this band need a solid 9 to 11 hours, and getting it is strongly linked to better attention, behaviour, learning, and emotional regulation. The biggest modern threat to children’s sleep is screens in the bedroom, which push bedtimes later and suppress melatonin. A consistent, screen-free wind-down routine is one of the highest-impact things a parent can do.

Teenagers (14–17 years)

Teenagers are caught in a biological trap. At puberty the circadian rhythm shifts later — a real, hormone-driven delay called sleep phase delay — so a teenager genuinely cannot fall asleep at 10 p.m. even when they try. Yet they still need 8 to 10 hours, and early school start times force them up before their cycles are finished. The result is chronic sleep debt across an entire age group.

If you’re a teen or a parent of one, the most effective tools are protecting morning daylight exposure, keeping a consistent wake time, and aligning bedtime with full sleep cycles so the limited hours available are used as efficiently as possible.

Young adults and adults (18–64 years)

This is the classic 7-to-9-hour band — equivalent to roughly five to six 90-minute sleep cycles. Within this range, individual needs vary based on genetics, physical activity, stress, illness, and recovery from previous short nights. Athletes and people doing intense physical or cognitive work often sit at the top of the range or beyond.

The biggest mistake adults make is treating 7–9 hours as optional and routinely running on 5–6. The damage from chronic mild sleep restriction accumulates quietly: impaired concentration, weakened immunity, weight gain, mood problems, and elevated long-term health risks. Unlike a single bad night, this kind of slow debt doesn’t announce itself — you simply adapt to functioning below your best and forget what fully rested feels like.

Older adults (65+ years)

A common myth is that older people need much less sleep. In truth their need drops only slightly, to about 7–8 hours, but their ability to sleep deeply declines. Deep N3 sleep becomes shorter and lighter, sleep gets more fragmented, and the body clock often shifts earlier — hence earlier bedtimes and earlier waking. Daytime light, physical activity, and a consistent routine help preserve sleep quality, while frequent night waking or daytime exhaustion is worth discussing with a doctor rather than dismissing as “just ageing.”

Quality matters as much as quantity

Two people can both sleep eight hours and feel completely different in the morning, because total hours are only half the story. The other half is whether those hours contain complete, undisturbed sleep cycles. Fragmented sleep — broken up by noise, alcohol, a too-warm room, or a baby — can leave you short on deep sleep and REM even when the clock says you slept plenty.

This is where timing helps. Whatever your age-appropriate target, aim to wake at the end of a cycle rather than the middle of one. The CycleBed calculator turns your target into specific bedtimes built from full 90-minute cycles, so the hours you do get are as restorative as possible.

How to find your personal number

The chart gives a range; your body knows the exact figure. To find it, pick a week with no early obligations, go to bed when you’re tired, and let yourself wake naturally without an alarm. After a few days of repaying any built-up sleep debt, your natural sleep length will settle around your true need. Note it, then build your schedule around waking at a full cycle close to that number.

Keep reading

• Sleep cycles explained: the four stages of sleep
• How to fall asleep faster
• The complete guide to power naps
• Sleep debt: what it is and how to recover

Ready to plan tonight? Use the sleep cycle calculator to find your ideal bedtime.