Sleep efficiency calculator
How much of your time in bed is actually spent asleep? Enter last night's times and we'll work out your sleep efficiency — the number sleep clinicians use to spot restless nights.
Last night
Sleep efficiency
88%
0%85%100%
Healthy: within the range sleep researchers consider good.
| Time in bed | 8 h 15 min |
|---|---|
| Time asleep | 7 h 15 min |
| Time awake in bed | 1 h |
How sleep efficiency is calculated
Sleep efficiency = total sleep time ÷ time in bed × 100. Time asleep is time in bed minus the minutes it took to fall asleep, the minutes awake in the night and any time lying awake before getting up.
Example: 8 hours in bed, 20 minutes to fall asleep, 25 minutes awake in the night, 15 minutes lying there before the alarm. Asleep = 480 − 60 = 420 minutes, so efficiency = 420 ÷ 480 = 87.5%.
Around 85% or higher is the threshold commonly used in sleep research and in the Pittsburgh Sleep Quality Index (Buysse et al., 1989) as "good" efficiency.
If your efficiency is low
Spending a lot of time awake in bed can teach your brain that bed is a place for lying awake. Cognitive behavioural therapy for insomnia (CBT-I), the first-line treatment recommended by the American College of Physicians, works partly by matching time in bed more closely to actual sleep.
- Get up at the same time every day, whatever the night was like.
- Go to bed when sleepy, not just when it's "bedtime".
- If you're awake for what feels like 20 minutes, get up and do something quiet in dim light until sleepy.
Questions people ask
What is a good sleep efficiency?
85% or higher is generally considered good for adults; above 90% is very efficient. Older adults often have somewhat lower efficiency.
How do I calculate sleep efficiency?
Divide the time you were actually asleep by the total time you spent in bed, then multiply by 100.
Why is my sleep efficiency low?
Common reasons include going to bed before you are sleepy, spending long periods in bed on phones or TV, caffeine or alcohol, noise, pain, and sleep disorders such as insomnia or sleep apnea.
Is my tracker's sleep efficiency accurate?
Wearables estimate wake and sleep from movement and heart rate. They are reasonable at total sleep time but often miss short awakenings, so efficiency may read higher than a sleep lab would measure.