Sleep Quality Index Calculator
Score your sleep across efficiency, latency, duration, disturbance, and daytime function — a structured self-assessment modelled on the components of validated sleep quality instruments.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| Sleep Quality Index Calculator | — | Score = sum of 6 component scores (0–18) | points |
Step-by-Step Examples
8 h in bed, 7.5 h asleep, 10 min latency, one waking, rarely sleepy, no medication, very good quality.
- Efficiency = 7.5 / 8 = 94% → 0
- Latency 10 min → 0, duration 7.5 h → 0
- Wakings, sleepiness, medication, subjective all 0
- Total = 0
8.5 h in bed, 6 h asleep, 45 min latency, three wakings, often sleepy, no medication, fairly bad.
- Efficiency = 6 / 8.5 = 71% → 1
- Latency 45 min → 2, duration 6 h → 1
- Wakings 3 → 2, sleepiness often → 2
- Subjective fairly bad → 2
- Total = 10
6 h in bed, 5.8 h asleep, 8 min latency, no wakings, often sleepy, no medication, fairly good.
- Efficiency = 97% → 0, latency → 0
- Duration 5.8 h → 2
- Sleepiness often → 1, subjective fairly good → 1
- Total = 4 — the problem is time in bed, not sleep quality
Real-World Applications
Common Mistakes to Avoid
Someone sleeping efficiently for six hours has a duration problem, not a quality problem. The interventions differ completely.
Extending time in bed usually lowers sleep efficiency and worsens insomnia. Sleep restriction therapy deliberately does the opposite.
Loud snoring, witnessed pauses in breathing, restless legs, or persistent daytime sleepiness point toward specific disorders that self-assessment cannot detect.