Defining Sleep Efficiency: How to Calculate and Ways to Improve It

Sleep Quality Improves, Insomnia Diminishes as Sleep Efficiency Increases

Calculating sleep efficiency may help to lead to changes that improve sleep quality and resolve insomnia
Calculating sleep efficiency may help to lead to changes that improve sleep quality and resolve insomnia. Stuart O'Sullivan/Getty Images

Insomnia is characterized by difficulty falling or returning to sleep. As it worsens, more of the time that is spent lying in bed is spent awake. It can be helpful to understand problems sleeping by examining sleep efficiency. This measurement may also prompt changes in sleep habits that may enhance the depth and quality of sleep. Learn how to improve sleep through the definition and calculation of sleep efficiency.

What Is the Definition and Calculation of Sleep Efficiency?

Sleep efficiency is the ratio of the total time spent asleep (total sleep time) in a night compared to the total amount of time spent in bed. For example, if a man spends 8 hours in bed on a given night, but only actually sleeps for four of those hours, his sleep efficiency for that evening would be 50% (four divided by eight multiplied by 100 percent). As another example, a woman who sleeps six out of the 8 hours spent in bed would have a sleep efficiency of 75% (six divided by eight multiplied by 100 percent).

If an individual spends the majority of the time that they are in bed actually asleep, than they are considered to be sleep efficient (or to have a high sleep efficiency). However, if an individual spends a lot of the total time that they are in bed awake, than that is not considered to be sleep efficient (or the person has a low sleep efficiency).

An efficient sleep leads to a deeper sleep of higher quality with fewer interruptions. It may result in feelings of energy and being well-rested upon awakening, while an inefficient sleep may lead to feelings of tiredness and restlessness. In order to achieve good sleep efficiency, it is recommended that extra time should not be spent in bed.

The Meaning of Different Sleep Efficiency Rates

A sleep efficiency of 85% or higher is considered to be normal, while a sleep efficiency anywhere above 90% is considered to be very good. A sleep efficiency of lower than 85% is considered poor, and is a sign that an individual needs to get more efficient sleep. Insomnia often leads to a sleep efficiency that is 75% or lower. When sleep efficiency is close to 100%, it may indicate the person is not getting enough hours of sleep due to inadequate time in bed to meet their sleep needs.

Ways to Improve Sleep Efficiency

There is a multitude of ways to improve sleep efficiency. Many of these suggestions may be incorporated into basic advice for improved sleep (called sleep hygiene) or as part of a structured treatment called cognitive behavioral therapy for insomnia (CBTI).

  • Create a Sleep Sanctuary

The first thing to do to improve sleep efficiency is to reserve the bed and bedroom as a space for sleep. This may involve eliminating all potential distractions when sleeping.

There should be no television on and no music playing. If you are accustomed to having the television or music on, you should work to break those habits and go to sleep in a quiet, dark, and peaceful atmosphere.

All lights should be off, especially flashing, blinking, or especially bright lights. Cell phones should not be looked at in bed, as the lights of the screen can work the stimulate the brain and keep it awake. The potential sounds of a cell phone should also be muted, and the best option is to leave the phone to charge in another room (such as the kitchen).

  • Enhance the Association Between the Bed and Sleep

The bed should not be used for activities other than sleep or sex. This should also help to improve sleep efficiency. Participating in activities other than sleeping in bed, such as reading a book or watching TV, trains you to associate the bed with awake-time activities. Lying awake and reading for 2 hours adds to the total time in bed, greatly reducing the calculated sleep efficiency. The bed should be associated with sleeping or falling asleep only, and thus all other activities should be eliminated from the bed.

  • Observe Stimulus Control and Get Up If Awake

According to the rules of stimulus control, if you are awake for longer than 15 to 20 minutes, it is recommended that you get up, leave the bedroom, and do something relaxing. Once you begin to feel sleepy again, return to the bedroom to sleep. This helps to retrain you to sleep better in bed.

  • Be Active During the Day and Exercise

Exercise is also suggested as a method to improve sleep efficiency. Exercising during the day can work to tire out the body, and thus when the time comes for sleep at the end of the day, the body will be ready and waiting.

  • Protect the Time Before Bed and Relax Before Going to Sleep

A relaxing activity is also often recommended for right before bed. This could include taking a shower or bath, or reading a book (somewhere other than in the bed). A calm, relaxing activity can help prepare the body for sleep and improve overall sleep efficiency.

  • Consider Sleep Consolidation to Enhance Your Sleep

Finally, if all else fails, sleep can be improved by observing sleep restriction or sleep consolidation. By reducing the time in bed to better reflect your sleep needs, you will spend more of the time in bed actually sleeping. This can be achieved by observing a fixed wake time and delaying the bedtime. Often it is helpful to restrict the total time in bed to 6 or 7 hours. It may take several days before the benefits of this change become apparent. If daytime sleepiness occurs, the total time in bed can be gradually extended until the sleep needs are fully met. It may be best to make these changes under the guidance of a sleep medicine specialist.

Continue Reading