Find the best time to sleep or wake up
based on natural 90-minute sleep cycles and the average time it takes to fall asleep.
Option A — I want to wake up at:
Option B — I go to bed at:
💡 Tip: The calculator adds 15 minutes as an average time to fall asleep.
Why this works (Science, simply explained)
Human sleep moves in cycles of roughly 90 minutes, rotating through light sleep, deep sleep, and REM sleep. Waking up near the end of a cycle tends to feel easier and more refreshing than waking mid-cycle.
Most adults need about 5–6 full cycles per night (≈ 7.5–9 hours total). This tool shows options based on 3–5 cycles so you can adapt to real life.
What the calculator assumes
- One sleep cycle ≈ 90 minutes
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