How to Use the Insomnia Severity Index Calculator
If falling asleep or staying asleep is a regular struggle, and it's dragging down how you feel during the day, it might not be just fatigue — it could be insomnia. This calculator uses the exact 7 questions from the Insomnia Severity Index (ISI), an internationally recognized scale developed by psychologist Charles Morin and used widely in sleep clinics and research.
Each question rates a different dimension — difficulty falling asleep, staying asleep, waking too early, satisfaction with sleep, interference with daily life, how noticeable the problem is to others, and how much distress it causes — on a 0-4 scale. The seven scores are added into a total ranging from 0 to 28: 0-7 means no clinically significant insomnia, 8-14 is subthreshold insomnia, 15-21 is moderate insomnia, and 22-28 is severe insomnia.
This result is a self-screening reference only and does not replace a clinical diagnosis. If your score falls in the moderate range or higher, or these sleep problems have lasted 3 months or more, it's worth talking to a sleep clinic or mental health professional to get properly evaluated and find the right treatment.
Frequently Asked Questions
A score of 0-7 means no clinically significant insomnia, 8-14 is subthreshold (mild) insomnia, 15-21 is moderate insomnia, and 22-28 is severe insomnia. Higher scores mean sleep problems are causing more distress and impairment.
Yes — the Insomnia Severity Index, developed by Charles Morin, is a widely used international standard screening and outcome tool in sleep clinics and research. This calculator is for self-screening; a formal diagnosis requires a clinical evaluation.
If you score 15 or above and it has lasted 3 months or longer, it may indicate chronic insomnia. It's worth seeing a sleep clinic or mental health professional for a proper evaluation and treatment plan.