Sleep Cycle Calculator
Plan sleep around 90-minute cycles to wake up feeling rested. Pick wake time or bedtime — OmniWhen suggests the other.
Sleep Cycle Planner
Plan sleep around 90-minute cycles to wake at the end of a cycle. Includes a 14-minute fall-asleep buffer.
About the Sleep Cycle Calculator
Enter a target wake time (or bedtime) and OmniWhen suggests times spaced 90 minutes apart, plus a 14-minute fall-asleep buffer when working backward from a wake time. Aim for 5–6 cycles for an adult.
Waking at the end of a cycle (light sleep) generally feels better than waking mid-cycle (deep sleep).
How it works
Sleep cycles are roughly 90 minutes long — light → deep → REM → light. Waking at the end of a cycle (in light sleep) generally feels easier than waking mid-cycle. The calculator suggests 3, 4, 5 and 6 cycles before or after your input time. When working backward from a wake-up time, it adds a 14-minute fall-asleep buffer.
Examples
- Wake at 06:30Bed at 21:16 (6 cycles, 9h sleep), 22:46 (5 cycles, 7.5h), 00:16 (4 cycles, 6h)
- Bed at 22:00 (asleep at 22:14)Wake at 02:44, 04:14, 05:44, 07:14