Sleep Efficiency Calculator
The gold-standard quantitative metric of sleep quality.
Time in bed
8h 0m
Total sleep time
7h 25m
Sleep efficiency
92.7%
Excellent
Benchmarks: ≥90% excellent · 85–89% normal · 75–84% fair · <75% poor
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Frequently asked questions
What is a good sleep efficiency?+
≥85% is normal, ≥90% is excellent. <75% is clinically significant inefficiency.
How is it different from total sleep time?+
Efficiency captures the ratio. Two people sleeping 7 hours can have very different recovery if one spent 7.8 hrs in bed and the other 9.3 hrs.
Should I trust my smartwatch's number?+
Wearables are accurate within ±15 min for healthy adults but over-estimate sleep by 30+ min in insomnia. Use them for trends.
How do I calculate sleep efficiency?+
Total time asleep ÷ total time in bed × 100. If you're in bed 8 hours and asleep 7, efficiency is 87.5%.
Why is bed restriction therapy effective?+
It compresses time in bed to match actual sleep, rapidly raising efficiency above 90% and rebuilding sleep pressure — a core technique in CBT-I.
Does age affect normal efficiency?+
Yes — efficiency naturally drops 5–10 points per decade after age 50 due to lighter sleep and more nighttime awakenings.
Can high efficiency be a bad sign?+
Sustained efficiency above 95% with daytime fatigue may indicate severe sleep deprivation — your body crashes the moment your head hits the pillow.
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