How is "Sleep Efficiency" calculated?

Sleep efficiency is calculated as the ratio of total sleep time to the time spent in bed, expressed as a percentage. This measure provides valuable insight into how effectively a person sleeps relative to the amount of time they are attempting to sleep. A higher sleep efficiency percentage indicates that an individual is spending most of their time in bed actually sleeping, which is generally a positive sign of sleep quality.

In practical terms, if someone is in bed for 8 hours but only sleeps for 6 hours, their sleep efficiency would be 75%. This metric is particularly useful in sleep studies and clinical settings, as it helps healthcare providers assess the overall quality of a person's sleep and identify potential issues such as insomnia or other sleep disorders.

The other options do not accurately represent how sleep efficiency is defined or calculated. For example, measuring the time awake during the night provides information about disturbances but does not give a complete picture of sleep efficiency. Similarly, counting awakenings or averaging sleep cycle duration offers insights into various aspects of sleep but does not directly relate to the calculation of sleep efficiency itself.