Sleep Efficiency Calculator: Time Asleep vs in Bed

Sleep efficiency calculator

Short answer

Sleep efficiency is the share of your time in bed spent asleep. 7 h 6 min asleep in 8 h in bed is 89%. A National Sleep Foundation expert panel treats 85% or more as an indicator of good sleep quality. Read it over a week of nights rather than from one.

Last reviewed 27 October 20261 published sourcesNot medical advice

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Sleep efficiency calculator

Your Apple Watch or the Health app shows time asleep; time in bed is from lights out to getting up.

Enter your time in bed and your time asleep.

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Sleep efficiency by time in bed and time awake in bed
Awake in bed	7 h in bed	8 h in bed	9 h in bed
15 min	96%	97%	97%
30 min	93%	94%	94%
45 min	89%	91%	92%
60 min	86%	88%	89%
90 min	79%	81%	83%

Awake in bed

7 h in bed

8 h in bed

9 h in bed

15 min

96%

97%

30 min

93%

94%

45 min

89%

91%

92%

60 min

86%

88%

89%

90 min

79%

81%

83%

The 85% marker

A National Sleep Foundation consensus panel reviewed 277 studies and voted on which measures indicate good sleep quality. They agreed that sleep continuity measures, including sleep efficiency, are appropriate indicators across the lifespan, and treated an efficiency of 85% or more as good (Ohayon et al., 2017 (NSF)).

Efficiency says how well you used your time in bed, not whether you slept enough. Check how much sleep you need with the sleep by age calculator, and plan a bedtime with the sleep calculator.

Common questions

What is a good sleep efficiency?

85% or more. A National Sleep Foundation expert panel agreed that sleep efficiency at or above that level indicates good sleep quality.

How do I find my time in bed and time asleep?

With Apple Watch sleep tracking, the Health app shows your time asleep for each night. Time in bed is from lights out until you get up; note it yourself or use your iPhone's sleep schedule.

Why is my sleep efficiency low?

Long stretches awake in bed lower it, whether falling asleep, waking in the night or lying in. One night says little. If it stays low for weeks, a clinician or sleep specialist can help.

Sources

Figures on this page were checked against these publications on 27 October 2026.

Ohayon M, Wickwire EM, Hirshkowitz M, Albert SM, Avidan A, Daly FJ, Dauvilliers Y, Ferri R, Fung C, Gozal D, Hazen N, Krystal A, Lichstein K, Mallampalli M, Plazzi G, Rawding R, Scheer FA, Somers V, Vitiello MV. National Sleep Foundation's sleep quality recommendations: first report. Sleep Health. 2017;3(1):6–19. doi.org/10.1016/j.sleh.2016.11.006

Sleep efficiency calculator