Fitbit has published the results of a study that uses their longitudinal sleep database to analyze millions of nights of Sleep Stages data to determine how age, gender, and duration affect sleep quality. (Sleep Stages is a relatively new Fitbit feature that "uses motion detection and heart rate variability to estimate the amount of time users spend awake in light, deep, and REM sleep each night.") Here are the findings: The average Fitbit user is in bed for 7 hours and 33 minutes but only gets 6 hours and 38 minutes of sleep. The remaining 55 minutes is spent restless or awake. That may seem like a lot, but it's actually pretty common. That said, 6 hours and 38 minutes is still shy of the 7+ hours the the CDC recommends adults get. For the second year in a row Fitbit data scientists found women get about 25 minutes more sleep on average each night compared to men. The percentage of time spent in each sleep stage was also similar -- until you factor in age. Fitbit data shows that men get a slightly higher percentage of deep sleep than women until around age 55 when women take the lead. Women win when it comes to REM, logging an average of 10 more minutes per night than men. Although women tend to average more REM than men over the course of their lifetime, the gap appears to widen around age 50.