Sleep Efficiency Calculator
Sleep efficiency is the share of your time in bed that you actually spend asleep: time asleep ÷ time in bed × 100. A sleep efficiency of 85% or higher is generally considered healthy.
What's my sleep efficiency?
Enter last night's times. Rough estimates are fine.
Sleep efficiency
90%
Time asleep
7 h 10 min
Time in bed
8 h
That's in the healthy range: you spend most of your time in bed asleep. If you still wake up tired, look at total hours with the sleep debt calculator.
How sleep efficiency is calculated
Divide the time you were actually asleep by the total time you spent in bed, then multiply by 100. Time asleep is your time in bed minus the minutes it took to fall asleep and any time you lay awake during the night.
Example: in bed from 11 PM to 7 AM is 8 hours. Twenty minutes to fall asleep plus 30 minutes awake in the night leaves 7 hours 10 minutes asleep, so 430 ÷ 480 × 100 = about 90% sleep efficiency.
How to improve your sleep efficiency
- Get up at the same time every day, including weekends.
- Go to bed when you're sleepy, not just because it's a certain time.
- If you've been awake for around 20 minutes, get up and do something calm in dim light until you feel sleepy again.
- Use your bed for sleep, not for scrolling, working or watching TV.
- Avoid caffeine in the afternoon and alcohol close to bedtime; both fragment sleep.
- Pick a bedtime that ends on a full sleep cycle with the sleep calculator.
When low sleep efficiency is worth checking
An occasional bad night is normal. If your efficiency stays below 85% for several weeks and you feel tired during the day, it can be a sign of insomnia. Cognitive behavioral therapy for insomnia (CBT-I), which works directly on time in bed and sleep efficiency, is the recommended first treatment, so it's worth raising with a doctor.
More free sleep tools
Sleep Calculator
Best bedtime or wake-up time based on 90-minute sleep cycles.
Nap Calculator
When to set your alarm for a power nap or a full-cycle nap.
Sleep Debt Calculator
How much sleep you owe from the past week, and how to pay it back.
REM Sleep Calculator
When each REM period happens and how much REM sleep you get.
Jet Lag Calculator
How long jet lag lasts and how to shift your sleep before you fly.
Frequently asked questions
What is a good sleep efficiency?
85% or higher is generally considered healthy for adults. Below that, you are spending a noticeable part of your time in bed awake, which is common with insomnia, stress or an irregular schedule.
Can sleep efficiency be too high?
A score close to 100% night after night can be a sign that you are short on sleep: you fall asleep the moment your head hits the pillow because your body is catching up. Check whether you are getting enough total hours.
Why is this different from my sleep tracker?
Trackers estimate when you are asleep from movement and heart rate, and each brand does it differently, so their numbers often disagree with each other and with your own estimate. Use one method consistently and watch the trend.
How can I improve my sleep efficiency?
Keep a fixed wake-up time, only go to bed when you feel sleepy, and get up if you've been lying awake for around 20 minutes. Spending less time in bed awake raises your efficiency, and usually makes it easier to fall asleep the next night.