Use the fibromyalgia WPI & Symptom Severity calculator below to estimate your Widespread Pain Index and Symptom Severity Score. This tool does not diagnose fibromyalgia.
Fibromyalgia WPI & Symptom Severity calculator
Tick body regions with pain in the past week for your Widespread Pain Index (WPI), rate core symptoms for the past week (0–3 each), and note somatic symptoms from the past six months. This calculator does not diagnose fibromyalgia.
Widespread Pain Index (WPI)
Painful regions in the past week — use the checklist below (not colour alone)
For education only — not a diagnosis. Scores here are estimates from the values you enter. Your clinician may
calculate WPI & SSS differently at appointments. Hurtl’s in-app WPI & SSS estimate is built from daily logs
and may differ from a single self-assessment.
WPI (Widespread Pain Index) counts painful body regions in the past week (0–19). SSS (Symptom Severity Score) rates core symptoms over the past week plus somatic symptoms from the past six months (0–12).
Together they form FS/PSD (Fibromyalgia Symptom / Polysymptomatic Distress scale) — the same combined total on a 0 to 31 scale.
Widespread Pain Index (WPI)
The WPI counts how many of 19 defined body regions have been painful in the past week. Typical regions include jaw, neck, back, chest, abdomen and limbs — left and right counted separately.
Symptom Severity Score (SSS)
Core symptoms rated 0 to 3 for the past week:
Fatigue
Waking unrefreshed
Cognitive symptoms
Somatic symptoms (headache, lower abdominal pain, depression) from the past six months — combined contribution capped at 3.
How scores are calculated
FS/PSD = WPI + SSS
Research criteria sometimes reference WPI ≥ 7 and SSS ≥ 5, or WPI 4–6 with SSS ≥ 9 — alongside duration and clinical evaluation. Only a clinician can interpret this in context.
Worked example
Component
Score
WPI
8
SSS
9
FS/PSD total
17
Tracking fibromyalgia over time
Log widespread pain, fatigue, sleep and cognitive symptoms — Hurtl builds a running FS/PSD estimate from your entries.
The WPI counts how many of 19 defined body regions have been painful in the past week. Each region counts once — left and right sides are scored separately. WPI ranges from 0 to 19.
What is the Symptom Severity Score?
The Symptom Severity Score (SSS) rates fatigue, waking unrefreshed and cognitive symptoms over the past week (0–3 each), plus somatic symptoms from the past six months (combined contribution capped at 3). SSS ranges from 0 to 12.
How do you calculate fibromyalgia WPI and SSS?
Count painful body regions for WPI. For SSS, add the three core symptom scores plus the somatic symptom contribution (capped at 3). Combined FS/PSD total = WPI + SSS (0 to 31).
Can this calculator diagnose fibromyalgia?
No. Fibromyalgia assessment requires symptom duration, clinical evaluation and ruling out other causes. WPI and SSS support assessment but do not diagnose fibromyalgia on their own.
Does Hurtl track fibromyalgia symptoms?
Yes. Hurtl calculates an FS/PSD estimate from your daily logs — widespread pain and symptom severity — with a 7-day trend on the Condition tab.
What is FS/PSD?
FS (Fibromyalgia Symptom scale) and PSD (Polysymptomatic Distress scale) are two names for the same combined total — WPI plus SSS on a 0 to 31 scale.
This article explains WPI and Symptom Severity for general information only. It is not medical advice, a diagnosis, or a recommendation to start, stop, or change treatment. Scores should be interpreted by your clinician in the context of your full clinical picture. Hurtl is not a medical device and does not provide clinical monitoring or treatment decisions.
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