Calculate sleep efficiency from time in bed.
Sleep efficiency is time asleep divided by time in bed, and it is the core metric behind sleep restriction therapy. Adding the three awake components — falling asleep, waking during the night and lying awake before getting up — gives total wakefulness in bed. Healthy adults sit at 85% or above; a low figure with plenty of time in bed points to spending too long there rather than to needing more.
Sleep efficiency
Efficiency = (time in bed minutes - onset - night awake - early wake) / time in bed minutes x 100
Sleep restriction should be undertaken with guidance, particularly where driving, shift work, epilepsy or bipolar disorder are involved. This calculator is informational and not a substitute for clinical care.
Eighty-five per cent or higher is considered normal for adults; above 90% is excellent. Consistently below 80% is a hallmark of insomnia.
Sleep restriction concentrates sleep pressure into a shorter window, which raises efficiency and rebuilds the association between bed and sleep. It is a core part of CBT for insomnia.
Falling asleep instantly and never waking can indicate insufficient sleep overall. Efficiency near 100% alongside short total sleep suggests sleep deprivation.