Sleep Quality Score
Not all sleep is equal. Eight hours of fragmented, shallow sleep leaves you nearly as tired as six hours of deep, uninterrupted sleep. This 8-question assessment scores your sleep quality on a 0–100 scale across four key domains: efficiency, timing, daytime functioning, and sleep hygiene. It tells you exactly where to focus.
What this assessment measures
The scoring model is calibrated against the Pittsburgh Sleep Quality Index (PSQI), a validated clinical instrument developed by Buysse et al. in 1989 that remains the gold standard for sleep quality assessment. The PSQI established that a composite score above a threshold distinguishes "poor sleepers" from "good sleepers" with high sensitivity and specificity. This tool maps to those norms, a score below 65 corresponds roughly to the clinical poor-sleeper threshold.
The four domains reflect what sleep research identifies as the independent dimensions of sleep health. Sleep efficiency, falling asleep quickly and staying asleep, is weighted most heavily (40%) because it drives the largest share of sleep quality outcomes. Circadian timing consistency (25%) comes second: irregular sleep schedules disrupt the circadian clock in ways that even adequate total sleep time can't fully compensate for.
Sleep efficiency: the core metric
Sleep efficiency encompasses sleep latency (how long it takes to fall asleep), sleep fragmentation (how often you wake), and total sleep duration. These three elements combine to determine how much restorative slow-wave and REM sleep you actually accumulate. Someone who lies in bed 9 hours but takes 45 minutes to fall asleep, wakes twice during the night, and rises feeling groggy may be getting less restorative sleep than someone who sleeps a solid 7 hours.
Clinically, sleep efficiency is often expressed as the percentage of time in bed actually spent asleep. Healthy sleepers typically achieve 85% or above. Below 75% is a marker used in clinical insomnia assessment.
The overlooked role of timing
Sleep timing consistency, going to bed and waking at roughly the same time each day, may be as important as total sleep duration. The circadian clock governs the release of melatonin, cortisol, body temperature rhythms, and dozens of other biological processes. Irregular sleep timing creates a state of chronic circadian disruption that researchers call "social jet lag."
Studies by Roenneberg et al. found that each hour of social jet lag was associated with a 33% increase in the odds of obesity, independent of total sleep duration. Irregular sleep timing also directly worsens subjective sleep quality and daytime alertness, even when total sleep hours are held constant.
The single most effective intervention most people can make is to anchor their wake time: choose a consistent wake time and maintain it seven days a week, including weekends. Everything else in sleep hygiene is secondary to this.
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Frequently asked questions
What is the Pittsburgh Sleep Quality Index (PSQI)?
The Pittsburgh Sleep Quality Index (PSQI) is a validated clinical tool developed by Buysse et al. (1989) at the University of Pittsburgh. It assesses sleep quality across seven components: subjective sleep quality, latency, duration, efficiency, disturbances, medication use, and daytime dysfunction. A PSQI score above 5 distinguishes poor sleepers from good sleepers with 89.6% sensitivity and 86.5% specificity. This tool uses a simplified 8-question version calibrated to PSQI norms.
What is a good sleep quality score?
On this calculator's 0–100 scale: 80–100 is Excellent (you're a consistently strong sleeper), 65–79 is Good (solid sleep with minor areas to improve), 50–64 is Fair (meaningful impairment in at least one domain), and below 50 is Poor (sleep issues are likely affecting your daily functioning). These thresholds are calibrated so that a score below 65 corresponds roughly to a PSQI score above 5, the clinical threshold for poor sleep quality.
What are the four sleep quality domains?
The four domains assessed are: (1) Sleep Efficiency, how well you fall asleep and stay asleep, weighted at 40% because it's the core of sleep quality; (2) Timing & Restedness, sleep schedule consistency and morning alertness, at 25%; (3) Daytime Functioning, sleepiness and alertness during waking hours, at 20%; and (4) Sleep Hygiene, pre-bed habits and behaviours, at 15%. The domain breakdown shows which area needs the most attention.
Is this a medical diagnostic tool?
No. This is an informational screening tool based on published sleep quality research methodology. It can help you understand patterns in your sleep and identify areas to improve. It cannot diagnose sleep disorders such as insomnia, sleep apnea, restless legs syndrome, or narcolepsy. If you score in the Poor or Fair range and have persistent sleep concerns, please consult a healthcare provider or sleep specialist.
Reviewed by the SleepTools Editorial Team · April 20, 2026
Not medical advice. For sleep disorders, consult a healthcare provider.