90 dakikalık uyku döngülerine göre en iyi uyanma veya uyuma zamanını hesaplayın.
Sleep is structured in 90-minute cycles, each moving through light sleep, deep sleep (slow-wave sleep), and REM sleep. Waking in the middle of a cycle — especially during deep sleep — causes sleep inertia: that groggy, disoriented feeling that can last 20–60 minutes. Waking at the end of a cycle, during light sleep, feels effortless.
The key insight: it is not just about hours slept, but where in the cycle you wake. 7.5 hours (5 complete cycles) often feels better than 8 hours if the extra 30 minutes interrupts a deep sleep cycle.
Most adults need 5–6 complete sleep cycles (7.5–9 hours). The calculator adds 14 minutes to fall-asleep time — the average sleep onset latency for most people. If you regularly fall asleep faster or slower, adjust your mental model accordingly.