A useful sleep diary is simple: each morning, write down your best estimate of when you tried to sleep, how long falling asleep took, how much time you spent awake overnight, when you woke for the day, and how the sleep felt. Do this every day, including weekends, for 7 to 14 days.
The goal is not a minute-by-minute reconstruction. It is a consistent record that shows your sleep schedule, night-to-night variation, and daytime experience. The Consensus Sleep Diary, a standard form developed with sleep specialists and potential users, provides a good core set of questions 1.
What is a sleep diary?
A sleep diary, sleep log, and sleep journal usually mean the same thing: a daily, self-reported record of sleep. It captures details a device cannot know, such as when you actually tried to fall asleep, how refreshed you felt, and whether pain, worry, noise, or a sick child affected the night.
A diary can help you:
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see whether your sleep and wake times change across the week
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estimate how long you spend trying to fall asleep or awake during the night
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connect sleep with naps, work shifts, caffeine, alcohol, medicines, symptoms, or stressful days
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give a healthcare provider a clearer history than you may be able to recall at an appointment
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follow changes during treatment, including cognitive behavioral therapy for insomnia (CBT-I)
A sleep diary does not diagnose insomnia, sleep apnea, or another sleep disorder by itself. Current insomnia guidance treats the diary as support for a clinical history, not as a stand-alone test. For an initial insomnia assessment, 7 to 14 days is generally recommended because one or two nights may not represent your usual pattern 2.
Free sleep diary template
You can download the Consensus Sleep Diary with instructions or the one-page NHLBI sleep diary. Both are free. If a clinic gave you its own form, use that version so you collect the information your clinician needs.
For a simple daily entry, copy this template into a notebook, notes app, or spreadsheet:
Date of morning entry:
- Time I got into bed:
- Time I tried to go to sleep:
- Estimated time it took to fall asleep:
- Number of times I remember waking:
- Estimated total time awake during those awakenings:
- Time of my final awakening:
- Time I got out of bed for the day:
- Sleep quality, from 1 (very poor) to 5 (very good):
- Naps yesterday, including timing and duration:
- Optional notes:
The timing, awakening, sleep-quality, and notes fields follow the core Consensus Sleep Diary. Naps and other notes are optional. They can cover factors relevant to you, such as caffeine or alcohol timing, sleep medicines, exercise, pain, illness, menstrual symptoms, shift work, travel, or an unusual interruption. The NHLBI diary also includes medicines, alcohol, caffeine, and daytime sleepiness 3.
More detail is not always better. Choose a few optional factors you genuinely want to compare with sleep. A form that takes two minutes and gets completed is more useful than a complicated one you stop using.
How to fill it out accurately
Complete it in the morning
Fill in the previous night's entry within about an hour of getting out of bed. This keeps the details fresh and matches the Consensus Sleep Diary instructions 1.
Do not check the clock during every awakening just to complete the diary. In the morning, give your best estimate instead. An estimate is not a mistake. It is what the diary is designed to collect 1.
If you sleep during the day because of shift work, complete the entry after your main sleep period rather than forcing it into a nighttime schedule.
Keep the time points separate
These entries sound similar but answer different questions:
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Got into bed is when you physically entered bed. You may still have been reading, talking, or watching something.
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Tried to sleep is when you stopped other activities and intended to fall asleep.
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Final awakening is the last time you woke before starting the day, even if you stayed in bed afterward.
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Got out of bed is when you actually left bed to begin your day.
Keeping these points separate helps distinguish sleep opportunity from sleep itself. For example, getting into bed at 10:00 p.m. but not trying to sleep until 11:15 p.m. is different from trying to sleep for that entire 75 minutes.
Estimate awakenings without chasing precision
Record awakenings you remember. For their duration, add your rough estimates together. If you remember being awake twice for about 10 minutes each, write two awakenings and 20 minutes awake.
You will not remember every brief arousal, and you do not need to. The diary captures your experience of the night. If you have no reasonable estimate, write “unsure” instead of inventing a precise number.
Include ordinary and unusual days
Continue for at least 7 days and preferably 14 when you are preparing for an insomnia assessment. Record workdays, days off, and weekends. Do not discard a poor night or a late night because it seems unrepresentative. Note the reason if you know it, such as travel, illness, an overnight shift, or caring for someone.
If you miss a morning, leave that entry blank or label it “missed.” Filling it in several days later defeats the purpose of a daily record.
How to read your sleep diary
Look for repeated patterns across the full week or two, not a verdict from a single night. Useful questions include:
- Are your wake times fairly stable, or do they shift by several hours?
- Do you spend much more time in bed than you estimate sleeping?
- Are sleep timing and quality different on workdays and days off?
- Do long or late naps tend to precede a harder night?
- Do certain symptoms, medicines, substances, or schedule changes appear near worse nights?
- Does daytime sleepiness or difficulty functioning continue even after nights with enough sleep opportunity?
A pattern is a clue, not proof that one habit caused another. For example, worse sleep after late caffeine may be worth testing with your clinician, but the diary alone cannot rule out stress, illness, schedule changes, or another explanation.
Optional calculations
You do not need to calculate anything unless your clinician or CBT-I program asks you to. If you want a basic summary:
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Time in bed is the time from getting into bed to getting out of bed.
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Estimated total sleep time is time in bed minus the estimated time awake before sleep, during the night, and after the final awakening.
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Estimated sleep efficiency is estimated total sleep time divided by time in bed, multiplied by 100.
For example, an estimated 6 hours of sleep during 8 hours in bed gives an estimated sleep efficiency of 75%. The Consensus Sleep Diary paper describes sleep efficiency as the percentage of time in bed spent asleep 1.
Treat that number as a description, not a grade or diagnosis. Do not sharply restrict your time in bed or change prescribed medicines based on a self-calculated percentage. If you are using sleep scheduling as part of CBT-I, follow the individualized plan from your clinician or treatment program.
Sleep diary vs. sleep tracker
A diary and a wearable answer different questions:
| Tool | What it starts with | What the sleep result represents | |---|---|---| | Sleep diary | Your morning recollection and experience | A subjective estimate of sleep timing, wakefulness, quality, and symptoms | | Consumer watch, ring, or app | Sensor signals such as movement and heart rate | An algorithm's estimate of sleep and, on some devices, sleep stages | | Clinical actigraphy | Repeated wrist-movement measurements | A clinician-interpreted estimate of rest and activity patterns | | Polysomnography | Brain waves, eye movements, muscle activity, breathing, and other signals | A clinical measurement used to score sleep and investigate specific disorders |
“Measured by a tracker” does not mean the device directly measured sleep. A consumer wearable measures physical signals, then infers when you were asleep. The American Academy of Sleep Medicine says consumer sleep technology should not replace validated diagnostic testing or a comprehensive evaluation 4.
Your diary and tracker may disagree, especially about time awake while you lay still. Do not edit the diary to match the device. Record your own estimate first. If a clinician wants both, bring both sets of information and let the mismatch become part of the discussion.
Medical actigraphy is also based on movement, but it is a clinical tool rather than a consumer sleep score. It can provide objective activity data over several days when a clinician needs another perspective. Even so, objective monitoring is not required for a routine insomnia diagnosis 5.
How a clinician may use your diary
A clinician can use the diary alongside your symptoms, health history, medicines, work schedule, and daytime functioning. It may help show an irregular sleep-wake pattern, insufficient opportunity for sleep, or the type and variability of an insomnia complaint. It can also provide a baseline before treatment and a consistent way to discuss progress.
The numbers do not establish a diagnosis on their own. Current European guidance says chronic insomnia is diagnosed from a clinical history that includes the sleep complaint, adequate opportunity to sleep, daytime effects, frequency, and duration. A sleep study is not routinely needed for insomnia alone, but may be appropriate when another sleep disorder is suspected or treatment has not worked as expected 2.
When to seek medical advice
Share your diary with a healthcare professional if sleep problems are affecting your daily activities. The NHLBI suggests keeping a diary for 1 to 2 weeks before an appointment and bringing information about sleep timing, naps, daytime sleepiness, caffeine, alcohol, and exercise 6.
Do not wait until you have finished the diary to contact a healthcare professional if sleepiness is making it hard to stay alert, or if a bed partner notices frequent loud snoring, breathing that starts and stops, or gasping. These can be symptoms of sleep apnea, which a diary cannot detect or safely rule out 7.
Frequently asked questions
Do sleep diary times need to be exact?
No. Use your best morning estimate and be consistent. Do not check the clock repeatedly overnight just to improve the log.
Is paper or an app better?
Use the format you are most likely to complete. Paper is simple and has no notifications. An app can be convenient, but its automatic tracker data should remain separate from your self-reported estimate unless your clinician says otherwise.
What date should I use for an overnight sleep?
Use the date of the morning when you wake up, unless your form gives different instructions. For example, sleep that begins Monday night and ends Tuesday morning goes on Tuesday's entry.
How long should I keep the diary?
Seven to 14 consecutive days is a useful starting point for insomnia assessment. Continue longer if your clinician asks, if you work a rotating schedule, or if you are using it to monitor treatment.
Can a sleep diary diagnose insomnia?
No. It organizes the information a healthcare professional uses during an assessment, but it cannot confirm insomnia or rule out another sleep disorder on its own.
