How much deep and REM sleep you need by age
Enter your time asleep and your deep and REM minutes. See how they compare with what's typical for your age, on Apple Watch or another tracker.
Add your age, time asleep and stages.
Deep and REM sleep by age
| Age | Deep sleep | Deep on Apple Watch | REM sleep |
|---|---|---|---|
| 20 | 20% · 90 min | 11% · 50 min | 24% · 108 min |
| 30 | 18% · 81 min | 10% · 45 min | 23% · 104 min |
| 40 | 16% · 72 min | 9% · 40 min | 22% · 99 min |
| 50 | 14% · 63 min | 8% · 36 min | 21% · 95 min |
| 60 | 12% · 54 min | 7% · 32 min | 20% · 90 min |
| 70 | 11% · 50 min | 6% · 27 min | 19% · 86 min |
| 80 | 10% · 45 min | 6% · 27 min | 18% · 81 min |
Typical share of the night in healthy adults, from sleep lab studies, with minutes for 7.5 hours asleep. Apple Watch reports about 55% of the deep sleep a lab finds, and REM within minutes. Ohayon et al., Sleep, 2004; Robbins et al., Sensors, 2024.
How much deep sleep and REM is normal?
A review of 65 sleep lab studies of healthy people found deep sleep falls by about 2% of the night every decade until around 60, then levels off. REM falls more slowly, from about 24% of the night at 20 to 18% at 80. A typical 40-year-old spends about 16% of the night in deep sleep and 22% in REM: about 70 and 100 minutes in 7.5 hours.
What your watch can tell
In a 2024 study against a full sleep lab, Apple Watch got REM within minutes. It read about 50 minutes of deep sleep when the lab found 94, and counted the rest as Core. So compare Apple Watch deep sleep with the Apple Watch column, not the lab one. Rings and straps read deep sleep closer to the lab.
Why it matters
In two US groups followed for years, every 5% less REM came with about 13% higher risk of death. In the Framingham Heart Study, each 1% of deep sleep lost per year came with 27% higher risk of dementia. Both are observational, so they show a link, not proof that more deep sleep or REM would change the outcome.
How to get more
Most of what raises deep sleep and REM raises sleep overall: enough hours, a steady bedtime, no alcohol close to bed, and a cool, dark room. REM comes mostly in the last hours of the night, so cutting sleep short cuts REM the most.
Questions
How much deep sleep do I need?
In a sleep lab, about 20% of the night at 20, falling to about 11% by 70. That's about 90 minutes at 20 and 50 minutes at 70 for 7.5 hours asleep. On Apple Watch, expect a little over half that.
How much REM sleep do I need?
About 18 to 24% of the night, depending on age, or roughly 80 to 110 minutes in 7.5 hours asleep.
Is Apple Watch deep sleep accurate?
It reads deep sleep low, about half of what a sleep lab finds, and REM about right. Use it to follow your own trend, and compare it with Apple Watch norms rather than lab ones.
Sources
- Meta-analysis of quantitative sleep parameters from childhood to old age in healthy individuals. Ohayon et al., Sleep, 2004.
- Accuracy of three commercial wearable devices for sleep tracking in healthy adults. Robbins et al., Sensors, 2024.
- Association of rapid eye movement sleep with mortality in middle-aged and older adults. Leary et al., JAMA Neurology, 2020.
- Association between slow-wave sleep loss and incident dementia. Himali et al., JAMA Neurology, 2023.
Go deeper: Deep sleep, REM and what your watch can tell