Answer the 9 statements of the Fatigue Severity Scale (Krupp et al., 1989), each rated 1 (strongly disagree) to 7 (strongly agree). This tool computes your total (9–63), your FSS score = total ÷ 9 (1.0–7.0), a per-item breakdown, and whether you are in the severe-fatigue range (mean ≥ 4.0) — all in your browser.
How accurately does each statement reflect your condition during the past week? Pick one number per item. (Items verbatim: Krupp et al., 1989.)
Example: rating every item 5 → total 45, FSS score = 45 ÷ 9 = 5.00 → severe-fatigue range.
The scoring rule is deliberately simple — the arithmetic is pinned by the test suite so the boundary is exact.
| Total | FSS score | Interpretation |
|---|---|---|
| 9–26 | 1.00–2.89 | Low fatigue impact (below cutoff) |
| 27–35 | 3.00–3.89 | Moderate fatigue impact (below cutoff) |
| 36–49 | 4.00–5.44 | Severe-fatigue range (cutoff ≥ 4.0 met) |
| 50–63 | 5.56–7.00 | High fatigue impact (well above cutoff) |
Boundary check: a total of 35 gives 35 / 9 = 3.89 (below the cutoff); a total of 36 gives 36 / 9 = 4.00 (cutoff met). Because item scores are whole numbers, there is no ambiguous case between 35.999 and 36.
Descriptive bands ("low", "moderate", "significant", "high") are illustrative only. The only published threshold is mean ≥ 4.0 for severe fatigue (Krupp et al., 1989).
An honest screening tool says what it is not:
Answers match the structured data below, byte for byte.
The Fatigue Severity Scale is a 9-item questionnaire developed by Krupp and colleagues (Krupp LB, LaRocca NG, Muir-Nash J, Steinberg AD. The fatigue severity scale: application to patients with multiple sclerosis and systemic lupus erythematosus. Archives of Neurology. 1989;46(1):112-119). It measures how much fatigue affects daily life. Each statement is rated from 1 (strongly disagree) to 7 (strongly agree), reflecting your condition during the past week.
Add the 9 item scores to get a total between 9 and 63, then divide by 9. The result is the FSS score, a mean between 1.0 and 7.0. Higher means greater fatigue impact. For example, rating every item 5 gives total 45 and an FSS score of 45 / 9 = 5.00. This tool computes the total, the mean, and the per-item breakdown automatically.
Research suggests a mean score of 4.0 or higher (total of 36 or more) indicates severe fatigue, while below 4.0 indicates non-severe fatigue. Because item scores are whole numbers, the boundary is clean: a total of 35 gives 35 / 9 = 3.89 (below the cutoff), and a total of 36 gives 36 / 9 = 4.00 (cutoff met). This tool flags the cutoff exactly.
No. The FSS is a screening and research instrument, not a diagnosis. A high score means fatigue is having a strong reported impact on your life; it cannot tell you why. If fatigue interferes with your work, family, or daily activities, discuss your results with a doctor or other qualified healthcare professional.
The scale was developed by Krupp et al. in 1989 and validated in people with multiple sclerosis and systemic lupus erythematosus alongside healthy adults. The original study reported high internal consistency (Cronbach's alpha 0.88) and good test-retest reliability, and the scale has since been used widely in fatigue research across many conditions.
The statements cover: motivation when fatigued; exercise bringing on fatigue; being easily fatigued; interference with physical functioning; fatigue causing frequent problems; fatigue preventing sustained physical functioning; interference with duties and responsibilities; fatigue being among your most disabling symptoms; and interference with work, family, or social life.
They measure different things. The FSS measures the impact of fatigue on functioning (9 items, 1-7 each, mean 1.0-7.0). The Epworth Sleepiness Scale measures daytime sleepiness, the likelihood of dozing in everyday situations (8 situations, 0-3 each, total 0-24). A person can be fatigued without being sleepy and vice versa. We also host an Epworth Sleepiness Scale calculator.
Yes. Many people repeat it every few weeks under similar conditions (for example, the same time of day) and watch the trend. A rising mean score means fatigue is having a larger reported impact. This is useful information to share with a clinician, but it is not a substitute for medical advice.
Treat it as a starting point for a conversation, not a conclusion. If your score is in the severe range, consider booking an appointment and bringing the per-item breakdown from this page, keeping a short diary of sleep, activity, and fatigue for a week or two, and noting any medications or health changes that coincide with worse fatigue. A clinician can investigate causes, which range from sleep disorders to thyroid problems to mood disorders.
No. Every calculation runs locally in your browser with JavaScript. There are no external requests, no accounts, no cookies for your answers, and nothing leaves your device.
Free tool by NRTechStudio
Explore similar music tools and calculators. 100% free, accurate, and runs completely in your browser without sign-up.
2 taps, no typing needed — diagnostics are sent automatically.