Wake up at the right moment in your sleep cycle — not in the middle of one.
Suggested bedtimes
Sleep happens in cycles of roughly 90 minutes, each containing lighter NREM stages and a period of REM sleep — where memory consolidation and emotional processing occur. Waking up naturally at the end of a cycle, rather than mid-cycle, helps you feel alert and rested. This calculator adds 15 minutes for you to fall asleep, then maps 4 to 6 complete cycles so you can pick the window that fits your schedule.
Based on 90-minute sleep cycle research. Sleep cycles vary by individual.