How long is one sleep cycle?

One sleep cycle lasts approximately 90 minutes and includes light sleep, deep sleep, and REM sleep stages.

How many sleep cycles do I need per night?

Most adults need 5 to 6 complete sleep cycles per night, totaling 7.5 to 9 hours of sleep.

What happens if I wake up mid sleep cycle?

Waking up mid-cycle causes sleep inertia — the groggy, disoriented feeling. Waking at the end of a 90-minute cycle feels more natural and refreshed.

REM Sleep Health - REM SLEEP CYCLE CALCULATOR

What Time Should I Go to Sleep? Complete Guide (2026)

What Time Should I Go to Sleep? Complete Guide (2026) Introduction You’ve probably had nights where you slept a full 8 hours and still woke up feeling like you hadn’t slept at all. And then there are those rare mornings where you wake up after just 6 hours feeling completely refreshed and energized. What’s the … Read more

What Is REM Sleep? How It Works and Why It Matters

What Is REM Sleep Cycle and Why Is It Important for Your Health? What Is the REM Sleep Cycle and Why Is It Important for Your Health? Sleep is not a uniform state where the brain simply “shuts off.” Instead, it moves through several stages in repeating cycles throughout the night. One of the most … Read more