Calculates optimal wake-up or bedtimes based on sleep cycles.
The sleep calculator suggests optimal bedtimes or wake times based on 90-minute sleep cycles, helping you wake feeling refreshed rather than groggy.
One sleep cycle ≈ 90 minutes (light → deep → REM) Optimal sleep = 5–6 complete cycles = 7.5–9 hours Wake time = Bedtime + (N × 90 min) + ~15 min to fall asleep
Need to wake at 6:30 AM. Subtract 15 min for sleep onset → 6:15 AM. 5 cycles back (7.5 h) → bedtime 10:45 PM. 6 cycles (9 h) → 9:15 PM.
Loading calculator…