# Sleep efficiency

Sleep efficiency is the percentage of your time in bed that you actually spend asleep. You calculate it as total sleep time divided by time in bed. In adults, a value of 85% or higher is generally regarded as healthy. Low sleep efficiency reflects fragmented or inefficient sleep. It is linked to daytime fatigue, impaired glucose metabolism, higher cardiovascular risk, and a poorer subjective quality of life.

## Sources

- Morin CM, Kowatch RA, Barry T, Walton E. (1993). Cognitive-behavior therapy for late-life insomnia. Journal of Consulting and Clinical Psychology. https://doi.org/10.1037/0022-006X.61.1.137

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_Canonical: https://longevity-switzerland.com/en/glossary/sleep-efficiency · Part of Longevity Cities · Updated 2026-06-22_