| Profile | Item scores (7 items) | Total | Category |
|---|---|---|---|
| Light sleep disruption | 1, 1, 0, 1, 1, 0, 1 | 5 | No clinically significant insomnia |
| Intermittent insomnia | 2, 1, 1, 2, 2, 1, 2 | 11 | Subthreshold insomnia |
| Persistent impairment | 3, 3, 2, 3, 3, 2, 3 | 19 | Moderate insomnia |
| Severe symptoms | 4, 4, 3, 4, 4, 3, 4 | 26 | Severe insomnia |
The Insomnia Severity Index total is the sum of seven item scores. Each item is scored from 0 to 4, so the total ranges from 0 to 28.
- Total ISI = q1 + q2 + q3 + q4 + q5 + q6 + q7
- 0–7 = No clinically significant insomnia
- 8–14 = Subthreshold insomnia
- 15–21 = Moderate insomnia
- 22–28 = Severe insomnia
- Answer each of the seven questions based on the last two weeks.
- Click Submit to calculate your total score and severity category.
- Review item scores to see which areas contribute most.
- Use Download CSV or Download PDF to save or share.
- Repeat weekly to track changes and response to routines.
What the ISI measures in seven items
The Insomnia Severity Index uses seven questions scored 0–4, producing a 0–28 total. Items cover sleep initiation, maintenance, early waking, satisfaction, daytime interference, noticeability, and distress. Because each item contributes equally, a one‑point change in any item shifts the total by one and can move a person across cut points.
Score bands and typical interpretation ranges
Totals are grouped as 0–7 (no clinically significant insomnia), 8–14 (subthreshold), 15–21 (moderate), and 22–28 (severe). In practice, a score of 14 sits one point below the moderate threshold, while 15 is the first point in the moderate band. Monitoring totals weekly helps reveal whether changes are stable rather than random night‑to‑night variation.
Using item patterns to target interventions
Two people can share the same total with different item profiles. For example, a total of 12 could come from high sleep‑onset difficulty with low daytime interference, or the reverse. Looking at the bar chart of item scores highlights which domains drive the result. Targeting the highest two items often yields the fastest measurable improvement.
Tracking change with a practical benchmark
Because the total is discrete, meaningful change can be tracked in small steps. A three‑point drop equals reducing one severe item by three levels or lowering three items by one level. A weekly series of totals can be compared against your baseline average. If the average falls from 18 to 13, the category typically shifts from moderate to subthreshold.
Exporting results for clinical conversations
CSV and PDF exports preserve the timestamp, total, category, and each item score. Sharing item‑level data helps clinicians distinguish insomnia from other contributors such as irregular schedules, mood symptoms, medication effects, or breathing‑related sleep disruption. Consistent documentation also supports structured approaches like CBT‑I and follow‑up adjustments.
Making the calculator part of a sleep routine
Complete the questionnaire based on the last two weeks, not just last night. Keep wake time consistent, reduce late caffeine, and protect a wind‑down period. Record bedtime, wake time, naps, and alcohol use alongside the score to interpret shifts with better context each week accurately. Recalculate on the same day each week, then compare totals and item bars. When distress is high or safety is affected, seek professional support.
1) How often should I calculate my ISI score?
Weekly is ideal. Using the same weekday reduces noise and makes category changes easier to interpret across consistent two‑week windows.
2) What does a high score on “worry or distress” mean?
It suggests sleep-related anxiety may be amplifying symptoms. Pairing relaxation routines with stimulus control can reduce pre‑sleep arousal and improve follow‑through.
3) Can two people have the same total but different problems?
Yes. The total is a sum, so different item combinations can match. Item bars help pinpoint whether onset, maintenance, daytime effects, or distress are dominant.
4) Is the ISI a diagnosis of insomnia?
No. It is a screening and tracking tool. Diagnosis requires clinical evaluation, duration criteria, and assessment of medical, psychiatric, and sleep‑disorder contributors.
5) Why does the calculator use the last two weeks?
A two‑week window smooths out single bad nights and reflects typical patterns. It also aligns with common monitoring periods used in structured treatment plans.
6) When should I seek professional help?
If sleep problems persist, worsen, impair daytime functioning, or involve safety concerns. Severe scores or distress are strong signals to consult a qualified clinician.