Adults are generally recommended to get 7–9 hours of sleep per night to support optimal health.
This range is the standard recommendation for healthy adults from major sleep-health organizations, including the National Sleep Foundation. Sleep supports memory, learning, emotional regulation, immune function, metabolism, and cardiovascular health. The right amount varies somewhat by individual, but regularly sleeping far below the range is associated with poorer health outcomes.
The recommendation is not a demand that every adult sleep exactly eight hours. Some people function well near seven hours, while others need closer to nine. Sleep quality, regularity, and timing also matter; eight hours of fragmented sleep may be less restorative than a continuous night of sleep.
Age is an important source of confusion. Teenagers generally need more sleep—about 8–10 hours—while older adults are typically advised to get 7–8 hours. Persistent difficulty sleeping, excessive daytime sleepiness, or loud snoring may signal a sleep disorder and deserves medical attention.