Sleep Efficiency Calculator

About this calculator

Sleep efficiency is the percentage of time spent actually asleep out of the total time spent in bed, calculated as (total sleep time ÷ time in bed) × 100, a core metric used alongside total sleep time and sleep latency in clinical sleep medicine, derived from polysomnography or actigraphy recordings. A sleep efficiency at or above roughly 85% is generally considered a marker of healthy sleep, while sustained values well below that are one of the diagnostic signals used in evaluating conditions like insomnia.

Cognitive behavioral therapy for insomnia (CBT-I), one of the leading evidence-based insomnia treatments, uses sleep efficiency directly to guide sleep-restriction therapy, deliberately limiting time in bed to match actual sleep time and then gradually expanding the window as efficiency improves, and sleep-tracking wearables report a version of this same metric to give users a single number summarizing how restful a night was.

Enter your total time asleep and total time spent in bed and this calculator returns your sleep efficiency percentage.