How Many Hours of Sleep Do You Need?
Start with sleep duration appropriate for your age, then allow time to fall asleep and for any planned wake periods. A fixed 90-minute cycle is a calculator assumption; it cannot tell which sleep stage you will be in when the alarm rings.
Updated 15 October 2026 · Educational guidance
| Age | Daily sleep |
|---|---|
| 4–12 months | 12–16 hours, including naps |
| 1–2 years | 11–14 hours, including naps |
| 3–5 years | 10–13 hours, including naps |
| 6–12 years | 9–12 hours |
| 13–17 years | 8–10 hours |
| 18–60 years | 7 or more hours |
| 61–64 years | 7–9 hours |
| 65 years and older | 7–8 hours |
Time in bed is not time asleep
If you go to bed at 10 pm and get up at 6 am, the available window is eight hours. Time spent falling asleep or awake overnight reduces actual sleep. For example, an assumed 20 minutes to settle plus a 20-minute wake period leaves about seven hours and twenty minutes asleep. This is planning arithmetic, not a measurement from a sleep study.
Use calculator options as estimates
Sleep cycles vary between people and across a night. Several suggested bedtimes can help compare schedules, but the tool cannot guarantee an easier wake-up or compensate for insufficient total sleep. Prefer an achievable routine over a precise-looking minute that regularly leaves you tired.
Keep a record of how you feel
Write down bedtime, wake time, naps and whether you felt refreshed. Note shifts, prayer breaks and caffeine timing when relevant. The same nominal number of hours can feel different when sleep is interrupted. Bring a record to a clinician if you continue to feel unrefreshed.
When to seek help
Persistent difficulty sleeping, repeated waking or daytime sleepiness deserves professional advice. Do not use a calculator to rule out a sleep disorder. If you are sleepy while driving or operating machinery, stop the activity safely rather than treating another cup of tea as a reliable solution.
Frequently asked questions
Does everyone need eight hours?
No. Guidance varies by age, and individual sleep need also differs. Use the age range and how you function as context.
Are 90-minute cycles exact?
No. They are a simplified planning assumption, not a prediction of your sleep stages.
Do naps count for babies and toddlers?
The CDC infant and toddler guidance includes naps. Adult night-sleep planning should not be applied to infants.
Sources
Educational information only. A calculator or a guide cannot diagnose a condition. Discuss concerning symptoms or results with a qualified healthcare professional.