Almost every sleep physician recommends adults sleep for 7 to 8 hours every night. But everybody is different, according to Dr. Neil Kline, a sleep physician and representative for the American Sleep Association. "You need what you need," says Kline. "Some people may only need 6 hours, while others won’t function as well unless they get 8. There isn’t one specific amount of sleep that every person needs."
If you feel drowsy during the day—at work, in the car—you’re not getting enough sleep, Kline says. It’s as simple as that. If you’re still unsure how many hours your body needs, make it a goal to lay your head for 7 to 8 hours a night to guarantee optimal mental and physical performance.