Sleep efficiency is a way to measure how effective you are as a sleeper. Good sleepers will sleep most of the time that they’re lying in bed. Poor sleepers, on the other hand, spend a lot of time in bed not sleeping. You don’t want to make a habit of doing that. If you do, your mind might start to associate your bed with being awake. And that can make the problem worse.

Suppose you sleep about 6 hours a night, but you spend about 8 hours in bed. To figure out your sleep efficiency number, you would take 6 hours and divide that by 8 hours. That would be about a 75% sleep efficiency. Good sleepers have a sleep efficiency of 90%. This is a good goal to aim for. Improving your sleep efficiency can help make your bed a stronger cue for sleep.