" Oftentimes, people want a straightforward answer to this question, but sleep need is a distribution on a bell curve. The American Academy of Sleep Medicine and the top 20 researchers in this field got together and wrote a consensus report that adults need at least seven to nine hours on a regular basis. That’s a big distribution and everyone’s a little bit different. Probably 99 percent of people need between seven and eight hours, 50 percent of people need between eight and eight and a half hours. In order to get that sleep amount, you need to allocate more time in bed than that. You said you wake up in the middle of the night, which a lot of people do, but if you’re staying up for a long time, maybe it’s more of a problem. It’s still considered healthy sleep if you spend more than 85 percent of time in bed asleep. That’s the cutoff for insomnia. "