Sleep efficiency is the difference between how much time you sleep in bed versus how much time you spend in bed. The effectiveness of this interplay between hormones and neurotransmitters that get you to fall asleep greatly assist in having high sleep efficiency. Sleep efficiency is scored as a percentage1. Anyone that scores over 85% is doing great.
Let’s do an example.
You didn’t sleep well two nights ago, so last night you decided to go to bed earlier.
- You went to bed at 9pm to watch a show, but didn’t try to fall asleep until 10pm
- You ended up falling asleep around 11:30pm
- You woke up at 3am, and couldn’t get back to sleep until 4am.
- You then woke up at 7:00am but didn’t get out of bed until 8am.
In other words:
- You spent a total of 11 hours (between 9pm-8am), or 660 minutes in bed.
- You spent 1 hour (60 minutes) in bed watching TV
- It took you 1.5 hours (90 minutes) to fall asleep.
- You spent 1 hour (60 minutes) awake throughout the night
- You took 1 hour (60 minutes) to get out of bed after waking up
I created a handy dandy spreadsheet so you don’t have to do the sleep efficiency math.
In any case, here is the calculation if you want to try it yourself:
Here’s how to calculate your sleep efficiency for this night:
Total time in bed (660 minutes)
– Total time awake in bed (time in bed before attempting to to sleep (60) + time it took you to fall asleep (90)+ time you were awake during the night (60)+ time you spent in bed after waking (60) =[270 minutes])
= actual sleep time: 390 minutes (6.5 hours)
divide your actual sleep time (390 minutes) by total time spent in bed (660 minutes) = 59%.
This number represents your sleep efficiency for that night. Again, the ideal is 85% or greater, though anything above 75% is decent.
Improving your sleep efficiency is one of the key pieces of overcoming insomnia.
If you haven’t already, you should start tracking your sleep as described in the “Mission” at the beginning of this week. This diary/ sleep restriction calculator will be very important as we move into next week.