The percentage of time spent actually sleeping versus total time in bed, a key indicator of sleep quality.
FULL EXPLANATION
Sleep efficiency is calculated as the ratio of total sleep time to time spent in bed, expressed as a percentage. It measures how effectively you're using your time in bed for actual sleep.
High sleep efficiency means you're spending most of your time in bed sleeping rather than lying awake. Low sleep efficiency often indicates insomnia, sleep fragmentation, or spending too much time in bed relative to sleep needs.
WHY IT MATTERS
Sleep efficiency is one of the most important indicators of sleep quality. Poor sleep efficiency leads to non-restorative sleep and daytime fatigue, even with adequate time in bed.
HOW TO IMPROVE
Improve sleep efficiency by maintaining consistent wake times, avoiding time in bed while awake, addressing underlying sleep disorders, and practicing sleep restriction therapy if needed.
NORMAL RANGES
Good sleep efficiency is 85% or higher. Excellent is 90%+. Below 80% may indicate a sleep problem. Very low efficiency (<75%) often requires clinical attention.
RELATED TERMS
REM Sleep
A sleep stage characterized by rapid eye movements, vivid dreaming, and muscle paralysis, critical for memory consolidation and emotional processing.
Sleep Latency
The time it takes to transition from full wakefulness to sleep after getting into bed with the intention to sleep.
Deep Sleep
The most restorative sleep stage characterized by slow brain waves, essential for physical recovery, immune function, and growth hormone release.
Sleep Quality
A measure of how well sleep restores and recovers the body, beyond simple sleep duration.
More in Sleep Science
View all →REM Sleep
Well-EstablishedA sleep stage characterized by rapid eye movements, vivid dreaming, and muscle paralysis, critical for memory consolidation and emotional processing.
Sleep Latency
Well-EstablishedThe time it takes to transition from full wakefulness to sleep after getting into bed with the intention to sleep.
Circadian Rhythm
Well-EstablishedThe roughly 24-hour internal biological clock that regulates sleep-wake cycles, hormone release, and other physiological processes.