Sleep efficiency
Sleep efficiency calculator
Sleep efficiency = time actually asleep ÷ time in bed. Most healthy adults run ≥ 85%. The metric is most useful for catching insomnia-type complaints: people in trouble usually spend extra time in bed trying to sleep, which lowers efficiency further and entrenches the problem.
Your time in bed is being used efficiently. This is the range associated with restorative sleep in healthy adults.
How to use the number
Track efficiency for 1–2 weeks before trying to interpret a single night. If your average sits below 85%, the evidence-based first move is the counter-intuitive one: shorten your time in bed to match your actual sleep, then expand gradually as efficiency climbs above 90%. This is sleep restriction therapy, the highest-evidence component of CBT-I.
Normative values shift with age: Ohayon's meta-analysis shows efficiency naturally declines about 1.5 percentage points per decade after age 25, mostly from increased nocturnal awakenings. That decline is not pathology — but if it brings you under 75% and you have daytime impairment, get evaluated.
Sources: Ohayon et al., Sleep 2004 (meta-analysis of norms)· Edinger et al., AASM 2021 CBT-I guideline