Sleepcyclescalculator
Free sleep cycle calculator that computes optimal bedtimes and wake-up times using 90-minute REM cycles to avoid mid-cycle waking
A free web-based sleep cycle calculator that computes optimal bedtimes and wake-up times using 90-minute sleep cycles to avoid waking during deep sleep and reduce grogginess. It serves general consumers planning overnight sleep or naps, including individuals seeking consistent sleep schedules without medical guidance. It is delivered as an instant browser tool with no sign-up, offering bedtime, wake-up and nap modes, adjustable fall-asleep buffers and 1-6 cycle options.
Key features
- 90-minute REM cycle timing
- Bedtime mode calculation
- Wake-up mode calculation
- Nap mode calculation
- 20-minute power nap timer
- 60-minute recovery nap timer
- 90-minute full cycle nap
- Adjustable fall-asleep buffer 0-30 min
- 1-6 cycle time options
- Sleep cycle chart 1.5-9 hours