Sleep Cycle Analyzer

Optimize your sleep schedule for better rest

Enter Your Sleep Schedule

What time do you go to bed?

What time do you wake up?

Understanding Sleep Cycles

90-Minute Cycles

Each complete sleep cycle lasts approximately 90 minutes, progressing through light sleep, deep sleep, and REM sleep.

Why Timing Matters

Waking up at the end of a cycle (during light sleep) makes you feel refreshed. Waking mid-cycle causes grogginess.

Ideal Sleep Duration

Most adults need 5-6 complete cycles (7.5-9 hours). Fewer than 4 cycles can impair cognitive function.

15 Minutes to Fall Asleep

We account for the average time it takes to fall asleep when calculating your cycles.

Interesting Sleep Facts

🦒Giraffes sleep only 30 minutes per day in short 5-minute bursts, while koalas sleep 22 hours

🧠During REM sleep, your brain is almost as active as when you're awake, processing memories and emotions

🌙Before electric lights, people slept in two shifts with a 'watch' period of wakefulness between them

🛏️The record for longest time without sleep is 11 days (264 hours), set by Randy Gardner in 1964

💤Humans spend about 1/3 of their lives sleeping - roughly 26 years for the average person

🐬Dolphins sleep with one half of their brain at a time, keeping one eye open to watch for predators

⏰Your body temperature drops 1-2°F during sleep, which is why a cool room helps you sleep better

😴Dreaming typically occurs every 90 minutes during sleep, with dreams getting longer as the night goes on