Sleep latency

Sleep latency is the time it takes to fall asleep from the moment of settling down to sleep. It is one way of describing how readily a person drifts off, and is sometimes used as a rough indicator of how well sleep timing and sleep pressure are matched.

What does it indicate?

Falling asleep almost instantly can be a sign of being overtired or short on sleep, because sleep pressure is very high. A consistently long sleep latency can suggest the opposite — a bedtime that is too early, or not enough accumulated tiredness — so the child is put down before their body is ready for sleep.

What affects it?

Sleep latency is influenced by how long a child has been awake, the timing of their last nap, the wind-down before bed, and the sleep environment. In sleep coaching it is one of several signals used to judge whether nap and bedtime timings are working, rather than a target in its own right.