About Sleep Quality Index (PSQI)
7 min read
PSQI Calculator: Score Your Sleep Quality with the Pittsburgh Sleep Quality Index
TL;DR: Rate each of the 7 PSQI components (sleep latency, duration, efficiency, disturbances, medication use, daytime dysfunction, subjective quality) on a 0–3 scale. The calculator sums all seven scores for a total between 0 and 21. A score of 5 or below indicates good sleep quality. Scores from 6 to 10 indicate poor sleep. Anything above 10 signals very poor sleep quality requiring attention.
Table of Contents
- What Is the PSQI?
- Who Should Use This Calculator
- The PSQI Formula
- How to Score Each Component: Step by Step
- Two Worked Examples
- Six Common Scoring Mistakes
- FAQ
- Assumptions and Limitations
- Conclusion
- Further Reading
What Is the PSQI?
Sleep quality is surprisingly hard to measure. You can track hours in bed, but that number alone says nothing about how long it took to fall asleep, how many times you woke up, or how wrecked you felt the next afternoon. The Pittsburgh Sleep Quality Index, published by Buysse and colleagues in 1989 in Psychiatry Research, was designed to collapse all of these dimensions into a single actionable number.
The PSQI has since become the most widely cited self-report sleep quality instrument in clinical research, referenced in over 10,000 published studies. It captures a full month of sleep behaviour across seven distinct components and produces a global score between 0 and 21. Clinicians use a cutoff of 5 to separate good sleepers from poor sleepers, a threshold that was validated in the original study with a diagnostic sensitivity of 89.6% and specificity of 86.5%.
What makes the PSQI useful outside the clinic is that it gives you a structured, repeatable way to evaluate your own sleep. Instead of vaguely feeling like your sleep "could be better," you get a number you can track over weeks and months as you adjust habits, medication, or routines.
Who Should Use This Calculator
- People with suspected insomnia who want a standardised baseline before speaking with a doctor. A PSQI score gives your clinician an immediate, quantified snapshot rather than a vague complaint.
- Shift workers and rotating-schedule professionals (nurses, pilots, residents) who need to monitor how schedule changes affect their sleep over time. Scoring monthly provides a clear trendline.
- Athletes and fitness enthusiasts tracking recovery quality. Sleep is the single most impactful recovery variable, and the PSQI captures dimensions that a simple hours-slept number misses.
- Older adults experiencing age-related sleep changes who want to distinguish normal ageing patterns from clinically poor sleep that warrants intervention.
- People starting a new sleep medication or supplement who need a before-and-after measurement to determine whether the intervention actually improved sleep quality, not just sleep duration.
- Anxiety or depression patients whose mental health treatment may be affecting sleep. The PSQI provides an objective tracking tool to share with a therapist or psychiatrist at each visit.
The PSQI Formula
PSQI Global Score = C1 + C2 + C3 + C4 + C5 + C6 + C7
Where each component (C1–C7) is scored 0–3:
C1: Subjective Sleep Quality
C2: Sleep Latency (time to fall asleep)
C3: Sleep Duration
C4: Sleep Efficiency (time asleep / time in bed)
C5: Sleep Disturbances
C6: Use of Sleep Medication
C7: Daytime Dysfunction
Score range: 0–21
0–5: Good sleep quality
6–10: Poor sleep quality
11–21: Very poor sleep quality
Source: Buysse DJ, Reynolds CF, Monk TH, Berman SR, Kupfer DJ. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Research. 1989;28(2):193–213.
How to Score Each Component: Step by Step
Each component uses a 0–3 scale where 0 means no difficulty and 3 means severe difficulty. The scoring reflects the past month of sleep behaviour, not a single night.
C1, Subjective Sleep Quality. Rate your overall sleep quality for the past month. 0 = very good, 1 = fairly good, 2 = fairly bad, 3 = very bad.
C2, Sleep Latency. How long does it typically take you to fall asleep? 0 = under 15 minutes, 1 = 16–30 minutes, 2 = 31–60 minutes, 3 = more than 60 minutes. If you also experience difficulty falling asleep three or more times per week, the component score may increase by one point (capped at 3).
C3, Sleep Duration. How many hours of actual sleep do you get per night? 0 = more than 7 hours, 1 = 6–7 hours, 2 = 5–6 hours, 3 = less than 5 hours.
C4, Sleep Efficiency. Calculate: (hours slept / hours in bed) x 100. 0 = 85% or higher, 1 = 75–84%, 2 = 65–74%, 3 = below 65%.
C5, Sleep Disturbances. How often do you wake up during the night or too early in the morning? This also includes disturbances from pain, breathing difficulty, temperature, or noise. 0 = not during the past month, 1 = less than once a week, 2 = once or twice a week, 3 = three or more times a week.
C6, Use of Sleep Medication. How often have you taken prescribed or over-the-counter sleep medication? 0 = not during the past month, 1 = less than once a week, 2 = once or twice a week, 3 = three or more times a week.
C7, Daytime Dysfunction. How often have you had trouble staying awake during daytime activities or lacked enthusiasm to get things done? 0 = not a problem, 1 = only a slight problem, 2 = a somewhat significant problem, 3 = a very significant problem.
After rating all seven, add the scores together. That total is your PSQI Global Score.
Two Worked Examples
Example 1: Margaret, 67, Retired with Chronic Insomnia
Margaret has struggled with sleep for years. She lies awake for over an hour most nights, sleeps roughly 4.5 hours, and takes prescription sleep medication nightly. During the day she frequently dozes off while reading.
| Component | Description | Score |
|---|---|---|
| C1: Subjective Quality | Rates sleep as "very bad" | 3 |
| C2: Sleep Latency | Takes over 60 minutes to fall asleep | 3 |
| C3: Sleep Duration | Less than 5 hours per night | 3 |
| C4: Sleep Efficiency | ~4.5 hrs slept / 8 hrs in bed = 56% | 3 |
| C5: Sleep Disturbances | Wakes 2–3 times nightly due to pain | 3 |
| C6: Sleep Medication | Takes medication every night | 3 |
| C7: Daytime Dysfunction | Falls asleep during activities regularly | 3 |
PSQI Global Score: 21 (Very Poor Sleep Quality)
Margaret's score hits the maximum. Every single component is at its worst possible rating. This profile is consistent with severe chronic insomnia, and the score provides strong clinical justification for a sleep medicine referral. Her physician can use this as a documented baseline before starting cognitive behavioural therapy for insomnia (CBT-I) or adjusting her medication regimen, then re-score monthly to track progress.
Example 2: Daniel, 23, Medical Resident on Rotating Night Shifts
Daniel works a schedule that alternates between day and night shifts every two weeks. He falls asleep within about 25 minutes, gets around 5.5 hours of sleep, and does not take sleep medication. He feels moderately drowsy during afternoon lectures.
| Component | Description | Score |
|---|---|---|
| C1: Subjective Quality | Rates sleep as "fairly bad" | 2 |
| C2: Sleep Latency | Falls asleep in 16–30 minutes | 1 |
| C3: Sleep Duration | Gets 5–6 hours per night | 2 |
| C4: Sleep Efficiency | ~5.5 hrs slept / 7 hrs in bed = 79% | 1 |
| C5: Sleep Disturbances | Wakes once or twice a week from noise | 1 |
| C6: Sleep Medication | No medication used | 0 |
| C7: Daytime Dysfunction | Moderate difficulty staying alert | 2 |
PSQI Global Score: 9 (Poor Sleep Quality)
Daniel's score falls squarely in the "poor" range. The main contributors are short sleep duration, low subjective quality, and daytime dysfunction. His sleep latency and efficiency are actually reasonable. This pattern is typical of shift work disorder, where circadian misalignment rather than an intrinsic sleep problem drives the score. For Daniel, blackout curtains, a consistent pre-sleep routine during night-shift blocks, and strategic caffeine timing are the most evidence-based interventions.
Six Common Scoring Mistakes
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Scoring a single bad night instead of the past month. The PSQI is designed to capture your typical sleep pattern over 30 days. One terrible night does not define your score. Average your experience across the full month.
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Confusing time in bed with time asleep. Sleep efficiency (C4) requires dividing actual sleep time by total time spent in bed. If you read in bed for 90 minutes before turning off the light, those 90 minutes count as time in bed but not time asleep.
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Ignoring partial medication use. Taking melatonin "just occasionally" still counts. If you took any sleep-promoting substance even once in the past month, your C6 score is at least 1, not 0.
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Underrating daytime dysfunction. Many people have normalised their afternoon fatigue. If you need caffeine to function past 2 PM or struggle to stay awake in meetings, that qualifies as at least a score of 1 or 2 on C7.
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Rounding sleep duration up. People consistently overestimate how much they actually sleep. If you go to bed at 11 PM and get up at 6:30 AM, you did not sleep 7.5 hours. Subtract the time it took to fall asleep and any nighttime awakenings. Actual sleep may be closer to 6 hours.
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Forgetting to include all disturbance types. C5 covers more than just waking up at night. Pain, breathing problems, bathroom trips, temperature discomfort, and nightmares all count toward disturbance frequency.
Assumptions and Limitations
- Assessment period. All component scores reflect the past 30 days. Scores based on shorter or longer periods are not directly comparable to published norms.
- Self-report bias. The PSQI relies entirely on subjective reporting. People tend to underestimate sleep latency and overestimate sleep duration compared to polysomnography measurements.
- Clinical cutoff. The score of 5 separating good from poor sleepers was validated in the original study population (psychiatric patients and controls). Some subsequent studies have proposed adjusted cutoffs for specific populations, including older adults and chronic pain patients.
- Component weighting. All seven components contribute equally to the global score. In practice, some components (sleep duration, sleep efficiency) may be more clinically significant than others depending on the individual.
- Not a diagnostic tool. A high PSQI score indicates likely sleep problems but does not identify the cause. Obstructive sleep apnoea, restless leg syndrome, and primary insomnia can all produce similar PSQI profiles but require very different treatments.
- Cultural and language factors. Translated versions of the PSQI have been validated in many languages, but subjective terms like "fairly good" and "fairly bad" may carry different weight across cultures.
Conclusion
The PSQI turns a subjective, hard-to-articulate experience into a number you can act on. Scoring yourself takes about five minutes. A result of 5 or below means your sleep is clinically adequate. A result between 6 and 10 means there are real problems worth addressing through habit changes or clinical consultation. Anything above 10 warrants a conversation with a healthcare provider.
The real value is in repeated measurement. A single score is a snapshot. Monthly scores over three to six months become a trendline that shows you whether interventions are working, whether seasonal patterns exist, or whether a slow decline is underway. Start with your baseline score today, record the date, and score again in 30 days.