The Short Answer
Most adults need 90 to 120 minutes of REM sleep per night. This represents 20 to 25 percent of total sleep time. For a 7 to 9 hour night, that means 1.5 to 2 hours in REM sleep spread across 4 to 6 cycles.
The more useful question is not how much REM you need in absolute terms but what percentage of your total sleep time is REM. A consistent REM percentage below 17 to 18 percent is a signal that something is suppressing REM specifically. Common culprits include alcohol, elevated sleep temperature, irregular timing, and certain medications.
How REM Sleep Is Distributed Across the Night
REM sleep is not distributed evenly across the night. The first REM cycle of the night, which occurs approximately 90 minutes after falling asleep, lasts only 10 to 15 minutes. Each subsequent REM cycle grows longer. By the fourth and fifth cycles, REM periods can last 45 to 60 minutes.
This distribution has an important practical implication: the majority of your REM sleep occurs in the final 2 to 3 hours of the night. Cutting your sleep from 8 hours to 6 hours does not simply reduce REM by 25 percent. It eliminates the longest and most restorative REM cycles disproportionately. Research suggests that 6 hours of sleep can mean 50 percent less REM than 8 hours.
REM Sleep Needs by Age
Newborns (0 to 3 months): Approximately 50 percent of total sleep time in REM. Newborns sleep 14 to 17 hours, meaning 7 to 9 hours of REM daily. The high proportion reflects the enormous neural development and learning occurring in early life.
Infants (4 to 11 months): REM decreases to approximately 30 to 40 percent of sleep. Still significantly higher than adult levels as brain development continues rapidly.
Children (1 to 12 years): REM stabilizes around 20 to 25 percent of sleep time, approaching adult patterns. Children sleep 9 to 11 hours, meaning 2 to 2.5 hours of REM nightly.
Teenagers (13 to 17 years): Adult REM percentages of 20 to 25 percent. Sleep needs remain higher than adults at 8 to 10 hours.
Adults (18 to 64 years): 20 to 25 percent REM. For 7 to 9 hours of sleep, this means 1.5 to 2 hours of REM nightly.
Older adults (65 and over): REM percentage tends to decline modestly to 15 to 20 percent of sleep time. Total sleep time also tends to decrease. This age-related decline in REM is associated with some of the cognitive changes of aging and is an active area of sleep research.
How to Know If You Are Getting Enough REM Sleep
The most direct method is using a consumer sleep tracker. Apple Watch Series 6 and later, Oura Ring, Fitbit, and Garmin devices all estimate sleep stages. They are not as precise as polysomnography conducted in a sleep laboratory, but they are accurate enough to track trends over time.
Track your REM percentage for 2 to 4 weeks without making any changes. This establishes your baseline. A consistently low REM percentage, below 17 to 18 percent for adults, suggests one or more of the following:
- Alcohol consumption within 3 to 4 hours of sleep
- Sleep surface temperature that is too warm
- Irregular sleep timing disrupting circadian REM scheduling
- Medications that suppress REM, including SSRIs, benzodiazepines, and some antihistamines
- Undiagnosed sleep apnea causing repeated micro-arousals
- Insufficient total sleep time eliminating late-night REM cycles
Can You Get Too Much REM Sleep
In healthy adults without underlying conditions, getting too much REM sleep through natural means is uncommon. REM is self-regulating: if you have been REM deprived, your brain will increase REM duration and intensity on subsequent nights, a process called REM rebound. This is normal and temporary.
Abnormally high REM percentages in some circumstances can indicate depression, certain medication effects, or narcolepsy. If your tracker consistently shows REM above 30 percent of total sleep time and you feel unrestored despite adequate sleep hours, discussing this with a healthcare provider is reasonable.
What to Do If Your REM Is Low
See our complete guide to increasing REM sleep for the full list of evidence-backed interventions ranked by impact. The three highest-leverage starting points for most people are: implementing a consistent wake time, stopping alcohol at least 3 hours before bed, and cooling your sleep surface to 65 to 68 degrees Fahrenheit.