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Free Fatigue Severity Scale Calculator

Score the standard published 9-item Fatigue Severity Scale (FSS) questionnaire.

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Scores the standard published 9-item Fatigue Severity Scale (FSS) questionnaire (Krupp LB, LaRocca NG, Muir-Nash J, Steinberg AD. Arch Neurol. 1989;46(10):1121-1123). Each item is scored 1 (strongly disagree) to 7 (strongly agree), and the standard scoring method is the mean of the 9 item scores. A commonly cited cutoff of 4 or higher (out of 7) suggests clinically significant fatigue. Same questionnaire-scoring pattern as the Epworth Sleepiness Scale and STOP-BANG tools already on this site. For general reference and educational purposes only — not a diagnosis. Consult a doctor for actual evaluation of fatigue.

How it works

Rate your agreement (1-7) with each of the 9 standard FSS statements. The tool averages the 9 scores.

  1. Enter 1. My motivation is lower when I am fatigued. (1=strongly disagree, 7=strongly agree).
  2. Enter 2. Exercise brings on my fatigue. (1=strongly disagree, 7=strongly agree).
  3. Enter 3. I am easily fatigued. (1=strongly disagree, 7=strongly agree).
  4. Enter 4. Fatigue interferes with my physical functioning. (1=strongly disagree, 7=strongly agree).
  5. Enter 5. Fatigue causes frequent problems for me. (1=strongly disagree, 7=strongly agree).
  6. Enter 6. My fatigue prevents sustained physical functioning. (1=strongly disagree, 7=strongly agree).
  7. Enter 7. Fatigue interferes with carrying out certain duties and responsibilities. (1=strongly disagree, 7=strongly agree).
  8. Enter 8. Fatigue is among my three most disabling symptoms. (1=strongly disagree, 7=strongly agree).
  9. Enter 9. Fatigue interferes with my work, family, or social life. (1=strongly disagree, 7=strongly agree).
  10. Click Calculate to see your results.

Examples

All items rated 1

FSS score = 9/9 = 1.0 (minimum possible, no fatigue impact indicated).

All items rated 7

FSS score = 63/9 = 7.0 (maximum possible).

Who should use it

  • Fatigue self-screening education.
  • Tracking fatigue impact over time.

Industry applications

  • Neurology/rheumatology clinical education
  • Patient-reported outcome measure reference

Advantages

  • Standard, widely-used published questionnaire.
  • Simple, transparent averaging method.

Limitations

  • Self-report only — no objective physiological measurement.
  • A high score does not identify the underlying cause of fatigue.

Common mistakes to avoid

  • Answering items based on a single unusual day rather than your typical experience over the past week or two, as the questionnaire intends.

Best practices

  • Answer based on your typical recent experience, not an outlier day.

Tips

  • The FSS was originally validated in multiple sclerosis and lupus patients but is now used more broadly as a general fatigue-impact screening questionnaire.

Frequently asked questions

Yes, with no signup and no limit on how many calculations you run.
A mean score at or above the commonly cited cutoff of 4 (out of 7) suggests clinically significant fatigue impact, per Krupp et al. (1989) — this is a screening tool, not a diagnosis.
No — the FSS is a self-report screening questionnaire, not a diagnostic test. Consult a doctor for actual evaluation of fatigue and its underlying causes.

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