Sleep Quality Calculator (PSQI)

Written by Ash K · Last updated: June 2026 · Sources cited below

The Pittsburgh Sleep Quality Index (PSQI) is a validated clinical instrument that measures sleep quality over the past month. Unlike a simple "how many hours did you sleep" question, the PSQI assesses seven components: subjective quality, latency, duration, efficiency, disturbances, medication use, and daytime dysfunction.

Developed by Buysse et al. at the University of Pittsburgh (1989), it has been used in over 10,000 published studies and remains the gold standard for sleep quality assessment.

What the PSQI Measures

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Key Takeaway: The PSQI scores 7 sleep components on a 0–3 scale each. Total score ranges 0–21. A score above 5 indicates "poor sleep quality" with 89.6% sensitivity and 86.5% specificity (Buysse et al., 1989). This isn't about hours — it's about whether your sleep is actually restorative.

Component	What it measures	Score range
Subjective quality	How you rate your sleep overall	0–3
Sleep latency	How long it takes to fall asleep	0–3
Sleep duration	Total hours of actual sleep	0–3
Sleep efficiency	% of time in bed actually sleeping	0–3
Sleep disturbances	Nighttime disruptions (pain, breathing, temperature)	0–3
Sleep medication	Use of prescribed or OTC sleep aids	0–3
Daytime dysfunction	How sleepiness affects daily functioning	0–3

Understanding Your PSQI Score

Score	Quality	Interpretation
0–5	Good sleep quality	Sleep is restorative; current habits working
6–10	Poor sleep quality	Meaningful impairment; improvement strategies recommended
11–15	Significantly poor	Substantial sleep dysfunction; professional evaluation warranted
16–21	Severely impaired	Severe disruption; medical evaluation recommended

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Note: The PSQI cutoff of 5 was established through validation against polysomnography (overnight sleep lab studies). It correctly identifies 89.6% of people with clinically poor sleep. However, some individuals with scores of 4–5 may still benefit from sleep improvement strategies.

PSQI 7 Components — Published Assessment Framework (Buysse 1989)

Sleep Efficiency: The Overlooked Metric

Sleep efficiency = (hours asleep / hours in bed) × 100. If you're in bed for 8 hours but sleeping 6, your efficiency is 75% — below the 85% threshold considered normal.

Low sleep efficiency is often the hidden problem. People report "I sleep 8 hours" when they actually lie awake for 2 of those hours. The PSQI captures this distinction.

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Tip: If your efficiency is below 85%, paradoxically, spending less time in bed can improve it. This is the basis of CBT-I (cognitive behavioral therapy for insomnia) — restrict bed time to match actual sleep time, rebuilding the association between bed and sleep. CBT-I is the first-line treatment for chronic insomnia per AASM guidelines.

When Poor Sleep Needs Professional Help

If your PSQI score is above 10, or if you experience any of the following, medical evaluation is appropriate: loud snoring with gasping or pauses (suggests sleep apnea), inability to fall asleep despite fatigue (insomnia), daytime sleepiness affecting driving or work safety, restless legs or periodic limb movements, sleepwalking or acting out dreams.

For related assessments, see our stress level test (stress is the #1 cause of poor sleep) and anxiety self-assessment (anxiety and insomnia frequently co-occur).

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Bottom Line: The PSQI measures sleep quality across 7 dimensions — not just hours. Score above 5 = poor sleep quality. The assessment takes 5 minutes and gives you a clinically validated baseline. Track your score every 1–3 months to measure whether sleep interventions are working.

Frequently Asked Questions

What is a good PSQI score?

A score of 0–5 indicates good sleep quality. Below 3 is excellent. Above 5 indicates poor sleep quality that may benefit from intervention.

How accurate is the PSQI?

The PSQI has 89.6% sensitivity and 86.5% specificity for identifying poor sleepers, validated against polysomnography. It's the most widely used and validated sleep quality instrument in clinical research.

How often should I retake the PSQI?

Every 1–3 months for trend tracking, or before/after sleep interventions to measure effectiveness.

Sources

Buysse DJ, et al. The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Research. 1989;28(2):193–213.
AASM. Clinical Practice Guideline for the Treatment of Chronic Insomnia in Adults. 2021.
Mollayeva T, et al. The PSQI as a screening tool for insomnia: a systematic review. Sleep Med Rev. 2016;25:52–73.