Sleep Efficiency Calculator
How efficient is your sleep?
Sleep efficiency = time asleep ÷ time in bed. A clinical metric that surfaces insomnia patterns even when your hours look fine.
What is a good sleep efficiency?
For healthy adults, 85% or higher is the clinical target. 90%+ is excellent. Sustained efficiency under 75% — or under 85% with difficulty initiating or maintaining sleep — is one of the diagnostic patterns for chronic insomnia (per AASM clinical guidelines).
How is sleep efficiency calculated?
The formula is (time asleep / time in bed) × 100. Time in bed = the gap between when you got into bed and when you got up. Time asleep = time in bed minus your sleep latency (how long it took to fall asleep) minus the total minutes you were awake at night.
Why this matters more than total hours
You can spend 9 hours in bed and only sleep 6 — that's 67% efficiency, and it produces the same fragmented, unrestorative night as a short sleeper. Efficiency catches what the hours number hides. It's also the metric most responsive to stimulus control and sleep restriction, the two cornerstones of CBT-I.
Interested in the full picture? Run the Sleep Age Calculator to see how all 10 sleep factors combine.