What Is a Good Sleep Efficiency?
Sleep efficiency is the percentage of your time in bed that you actually spend asleep. 85% or higher is generally considered good; 90%+ is excellent. Below about 75% usually means you're spending a lot of the night awake — falling asleep slowly, waking often, or lingering in bed scrolling.
How sleep efficiency is calculated
The formula is simple:
Sleep efficiency = (time asleep ÷ time in bed) × 100
Example: you're in bed from 23:00 to 07:00 (8 hours) but asleep for 7 hours and 12 minutes. That's 7.2 ÷ 8 = 90% efficiency — a very good night. The same 8 hours in bed with only 6 hours asleep is 75%, a sign that something is fragmenting your sleep.
What the ranges mean
- 90–100%: Excellent. (Consistently near 100% with short nights can also mean you're under-sleeping — you fall asleep instantly because you're exhausted.)
- 85–89%: Good, typical for healthy sleepers.
- 75–84%: Fair — worth looking at evening habits and wake-ups.
- Below 75%: Poor — a pattern here is worth taking seriously, and discussing with a doctor if it persists.
How to improve your sleep efficiency
- Use the bed only for sleep. Scrolling in bed trains your brain that bed = awake time. If that's your weakness, block apps at night.
- Go to bed sleepy, not early. More time in bed without more sleep lowers efficiency. Match time in bed to actual sleep need.
- Keep a consistent schedule. A stable bedtime and wake time anchor your body clock — see how to fix your sleep schedule.
- Watch alcohol and late caffeine. Both fragment the second half of the night.
- If you can't sleep after ~20 minutes, get up, do something calm and dim, and return when sleepy. Counterintuitive, but it protects the bed–sleep association.
Track it automatically with Lunomia
You don't need a spreadsheet. Lunomia calculates your sleep efficiency every night from your Apple Watch data — time asleep vs time in bed — and charts it in the Trends tab alongside sleep duration, sleep stages and bedtime consistency. Change one habit, then watch the efficiency line for two weeks: that's how you know whether it actually worked. And every night gets a sleep animal — efficient sleepers see a lot of koalas and bears; fragmented nights bring out the raccoons.
Good sleep ≠ 100%. Brief awakenings between sleep cycles are physiologically normal. Aim for a stable 85–95%, not perfection.
Know your sleep efficiency every morning
Automatic, private sleep analysis from your Apple Watch. Free download.
