REM sleep typically occupies 20–25% of total sleep in adult humans: about 90–120 minutes of a night's sleep. The first REM episode occurs about 70 minutes after falling asleep. Cycles of about 90 minutes each follow, with each cycle including a larger proportion of REM sleep.

How much REM sleep do you need?

On average you'll go through 3-5 REM cycles per night, with each episode getting longer as the night progresses. The final one may last roughly an hour. For healthy adults, spending 20-25% of your time asleep in the REM stage is a good goal. If you get 7-8 hours of sleep, around 90 minutes of that should be REM.

What is normal rapid eye movement?

Rapid eye movement (REM) sleep, or stage R, usually starts about 90 minutes after you fall asleep. Brain activity increases, your eyes dart around quickly, and your pulse, blood pressure, and breathing speed up. This is also when you do most of your dreaming. REM sleep is important for learning and memory.