Better Sleep Diary
Get the appGet app

Sources

Where our facts come from

Every fact about sleep on this site comes from one of these. We read each source and recheck it from time to time.

  1. Measuring Sleep Efficiency: What Should the Denominator Be?. Journal of Clinical Sleep Medicine, 2016.Sleep efficiency is usually total sleep time divided by time in bed; insomnia treatment commonly uses 85% as its threshold. Checked 7 November 2026.
  2. The Consensus Sleep Diary: Standardizing Prospective Sleep Self-Monitoring. Sleep, 2012.The sleep diary as the standard for describing your own sleep, the items it asks, and filling it in each morning. Checked 7 November 2026.
  3. Keeping a sleep diary. Oxford Health NHS Foundation Trust.Keep a sleep diary every day for 2 weeks, within an hour of getting up if you can. Checked 7 November 2026.
  4. Clinical Guideline for the Evaluation and Management of Chronic Insomnia in Adults. American Academy of Sleep Medicine, Journal of Clinical Sleep Medicine, 2008.A two-week sleep log before the first visit, what it records, and how total sleep time and sleep efficiency are worked out from it. Checked 7 November 2026.
  5. Behavioral and psychological treatments for chronic insomnia disorder in adults. American Academy of Sleep Medicine, Journal of Clinical Sleep Medicine, 2021.CBT-I is the recommended treatment for chronic insomnia, and it is guided by sleep diaries kept through treatment. Checked 7 November 2026.
  6. Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed. Journal of Clinical Sleep Medicine, 2013.A large dose of caffeine 6 hours before bed still cut measured sleep by more than an hour. Checked 7 November 2026.
  7. Alcohol and sleep I: effects on normal sleep. Alcoholism: Clinical and Experimental Research, 2013.Alcohol helps you fall asleep sooner but disturbs sleep in the second half of the night. Checked 7 November 2026.
  8. Insomnia. NHS.Symptoms, common causes, habits to change, and when to see a GP. Checked 7 November 2026.
  9. Consumer Sleep Technology: An American Academy of Sleep Medicine Position Statement. Journal of Clinical Sleep Medicine, 2018.Consumer sleep trackers can't diagnose or treat sleep disorders and don't replace validated tools. Checked 7 November 2026.

Nothing on this site is medical advice. If poor sleep has gone on for months or makes the day hard to cope with, see your doctor.