How Much Sleep Do You Need by Age?
Sleep needs change a lot across a lifetime — a newborn sleeps roughly twice as long as their grandparent. Here's how many hours each age group needs, drawn from the HSE, the American Academy of Sleep Medicine (AASM) and the National Sleep Foundation, plus how to tell when you're falling short.
Written by Seán — Lead Reviewer, MattressReviews.ie
Testing team: Aoife (Side Sleeper Specialist), Ciarán (Back Sleeper Specialist), Siobhán (Combination Sleeper Specialist) & Oisín (Stomach Sleeper Specialist)
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| Age group | Age | Recommended sleep |
|---|---|---|
| Newborns | 0–3 months | 14–17 hours |
| Infants | 4–12 months | 12–16 hours |
| Toddlers | 1–2 years | 11–14 hours |
| Pre-schoolers | 3–5 years | 10–13 hours |
| School-age children | 6–12 years | 9–12 hours |
| Teenagers | 13–18 years | 8–10 hours |
| Adults | 18–64 years | 7–9 hours |
| Older adults | 65+ years | 7–8 hours |
Figures for under-18s follow the AASM consensus statement (echoed by the HSE); adult and older-adult figures follow the National Sleep Foundation. Ranges allow for normal variation — an hour either side can still be healthy for some people.
A note on health advice: This guide is for general information only and is not medical advice. Sleep problems can have many causes. If poor sleep is affecting your daily life, lasts more than a few weeks, or you suspect a condition such as insomnia or sleep apnoea, speak to your GP. In Ireland you can also find guidance at HSE.ie.
Why sleep needs change with age
Sleep does different jobs at different stages of life, so the amount we need tracks what the body and brain are busy doing.
Babies and young children
The first years are a period of intense brain development and physical growth. Much of it happens during sleep — which is why infants need up to 16 hours, spread across naps and night-time, and why protecting sleep matters so much in early childhood.
Teenagers
Teenagers still need 8–10 hours, but puberty shifts the body clock later: the hormone melatonin is released later in the evening, so they genuinely aren't sleepy until late — then have to wake early for school. This is biology, not laziness.
Adults and older adults
The requirement settles at 7–9 hours in adulthood and barely drops after 65. Older adults often sleep less, but that's usually because sleep becomes lighter and more easily disturbed — the underlying need is much the same.
The Irish teenager problem
Most Irish secondary schools start between 8:40 and 9:00 AM, with many students facing a long commute before that. To get the recommended 8–10 hours, a teen rising at 7:00 AM would need to be asleep by 9:00–11:00 PM — but their delayed body clock often won't let them drift off until well after 11.
The result is chronic, built-in sleep debt on school nights. International research on later and flexible start times consistently finds that even a modest delay lets teenagers sleep significantly longer, with measurable gains in mood, well-being and academic performance — because it aligns the school day with adolescent biology rather than fighting it.
Signs you're not getting enough sleep
The clearest sign is needing an alarm to wake and feeling you could easily sleep more. Other common day-to-day signals include:
The odd bad night is normal. But if poor or insufficient sleep persists for more than a few weeks and affects your daily life, it's worth talking to your GP — it can point to insomnia, sleep apnoea or another treatable issue.
Quality matters as much as quantity
Hitting your hours is the goal, but they only count if the sleep is good. Eight broken hours can leave you more tired than seven solid ones, because waking repeatedly stops you reaching the deep and REM stages that do the real restorative work.
A few things make the biggest difference to quality: a consistent sleep and wake schedule, a cool and dark bedroom, limiting caffeine and alcohol later in the day, and a comfortable, supportive bed. Get those right and the same number of hours will leave you far more refreshed.
Want to make the hours you do get land better? Our sleep calculator works out bedtimes around 90-minute sleep cycles, and getting your bedroom temperature right is one of the easiest quality wins.
Getting the hours but still tired?
The bed itself is often the missing piece. Our 2-minute quiz matches you to the right mattress type, firmness and size for your age and how you sleep — no email required.
Take the 2-minute mattress quiz →Frequently Asked Questions
Keep reading
- → Sleep calculator: what time should I go to bed? — turn your target hours into a bedtime.
- → Best kids' mattresses in Ireland — support those crucial growing-years hours.
- → Best mattresses for seniors — easier rest for lighter, later-life sleep.
- → Bedroom temperature for better sleep — protect the quality of every hour.
Sources
- American Academy of Sleep Medicine — Recommended Amount of Sleep for Pediatric Populations: A Consensus Statement (2016). View source
- National Sleep Foundation — Sleep Time Duration Recommendations (2015). View source
- HSE — Babies and children: Sleep. View source