Work out sleep time instantly with clear inputs, formula shown and shareable results.
Time in bed is not sleep. Subtracting sleep latency and time awake during the night gives actual sleep, and the ratio of the two is sleep efficiency — above 85% is considered good, and consistently below that is a marker clinicians look at.
Sleep efficiency
sleep = time in bed - latency - awake time; efficiency = sleep / time in bed
10-20 minutes. Falling asleep in under five minutes suggests significant sleep debt; over 30 minutes regularly suggests insomnia.
Most people wake several times a night without remembering it. Longer awakenings fragment sleep architecture and reduce restorative deep and REM stages.