Sleep Cycle Calculator

1. A sleep cycle refers to the biological rhythm of sleep. A normal sleep cycle consists of two phases: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.

2. Non-REM sleep and REM sleep alternate; one cycle consists of this alternation and typically lasts 90–100 minutes.

3. The NREM phase lasts 60–70 minutes, while the REM phase lasts 15–30 minutes.

4. Typically, sleep involves five cycles, which ensure adequate sleep duration and quality, generally lasting 6–8 hours.