Enter your wake time and the minimum sleep you want, and you'll get three bedtime candidates — minimum, recommended, and with room for recovery — built around 90-minute cycles. Example: for a 6 a.m. wake and 7 hours wanted, the recommended bedtime is around 10:45 p.m. The 15-minute fall-asleep buffer is added automatically.
Each row works backwards from your wake time. The Recommended row aligns with the adult sleep range commonly cited by public health bodies — around 7 to 9 hours (CDC, AASM).
The Minimum row is a floor that lets you function the next day, but using it night after night tends to lower focus and mood. The Extended row leaves room to repay sleep debt or to recover from illness.
Bedtime works better as a window than a point. Aiming for ±15 minutes around your row is realistic and easier to keep up with.
General guidance only, not medical advice.
Recommended sleep length shifts with age. The figures below summarize the ranges from the American Academy of Sleep Medicine (AASM) and the CDC. Treat them as a starting point — individual needs vary.
| Teens (14–17) | 8–10 hours |
|---|---|
| Young adults (18–25) | 7–9 hours |
| Adults (26–64) | 7–9 hours |
| Older adults (65+) | 7–8 hours |
These reference ranges assume healthy adults. Pregnancy, recovery from illness, and shift work may shift the target.
Minimum is a floor for getting through the next day (around 6 hours). Recommended sits inside the 7–9 hour adult range cited by the CDC and AASM. More recovery is for nights when you need to repay sleep debt or recover from illness. Using Minimum every night is not advised.
Healthy adults usually fall asleep in 10 to 20 minutes, with 15 minutes as a common default. If 30+ minutes happens several nights in a row, set a longer fall-asleep value and move bedtime earlier.
It is an average. Real cycles often run 80 to 110 minutes and shift across the night. Use this tool as a rough plan and allow ±15 minutes of drift.
No. This is general guidance. If you have chronic insomnia, strong daytime sleepiness, or snoring or breathing pauses noted by others, please speak with a sleep clinic or your physician.