Amieryl — Everyday Sleep Guide | amieryl.life
Recommended sleep duration by age group, plus the signs that you are carrying chronic sleep debt.
The starting point for any change to your sleep is knowing your target number. Adults are generally recommended 7 or more hours of sleep per night; teenagers need 8 to 10 hours. These figures are the benchmark against which you measure your actual week — without them, 'I sleep fine' is an opinion rather than a measurement.
Sleep debt is the gap between that target and what you actually get, and it accumulates quietly. One or two short nights are manageable, but a pattern of 5–6 hour nights shifts daytime alertness, reaction time and mood before you consciously notice the change. The practical test: if you fall asleep within minutes of lying down every night, you are probably carrying debt — healthy sleep onset takes roughly 10–20 minutes.
Signs of chronic sleep debt are consistent and easy to recognise once you look for them: daytime sleepiness that caffeine no longer fixes, rising irritability, difficulty concentrating, and needing 10+ hours on the weekend after short weeknights. Weekend oversleep is repayment, not preference — the durable fix is to raise the weekday average rather than keep borrowing against Saturday and Sunday.
On narrow screens, swipe or scroll the plate sideways.
Age changes the requirement but not the structure. Whether you need 7 hours or 10, your night still cycles through non-REM and REM stages roughly every 90 minutes. Cutting the night short does not compress these cycles — it truncates them, usually at the end of the night, where much of the REM sleep sits. This is why a 5-hour night is not simply a shorter version of an 8-hour night; it is a structurally different one.
A practical way to find your own number: keep a simple log for two weeks — bedtime, wake time, and a 1–5 daytime alertness rating. Compare the average against the recommended figures for your age group, and note which nights you felt best. If your best nights cluster around 8 hours, that is your working target even if the general recommendation for adults is 7 or more.
The next step is to protect that number with cut-off times: last caffeine 5–6 hours before bed, screens off 60–90 minutes before bed, and a bedroom at about 18 °C (65 °F). Those three variables are covered in the evening routine and bedroom setup pages.
Further reading