What is the sleep efficiency?

Written by Jonathan
Last update

What's being measured?

Sleep efficiency is the time spent in bed asleep. We get this number by dividing the amount of time spent asleep by the amount of time between the moment the user wishes to sleep and the end of the record.

How does Dreem know when a user "wishes to sleep"?

Dreem considers the user "wishes to sleep" when they stay with their eyes closed, not moving.

Here's an example

The user goes to be at midnight, takes 30 minutes to fall asleep, wakes up for 30 minutes during the night before waking up at 7 am. The user's total sleep time is 6 hours and their time spent in bed is 7 hours. So the user's sleep efficiency is 6/7= 86%.

How to interpret this measurement

If your sleep efficiency is very high, this means that all your time spent in bed is spent sleeping. Any efficiency over 90% is typically considered good. REMINDER: Sleep efficiency is a ratio, it doesn't give any indication of sleep length. A very good sleep efficiency can be associated with a very short night.

A score is given to sleep efficiency according to its value:

Sleep efficiency Score attributed Comments
+ 90% 5 Excellent
85-90% 4 Very good
80-85% 3 Good
75-80% 2 Average
- 75% 1 Poor


Why is this measurement important?

This measurement is used by sleep specialists to quantify insomnia. When treating insomnia, it's this variable that we closely monitor and aim to improve.

Where can I find this measurement in the app?

Tap on the night card to open the "Quality" page.