Fatigue Severity Scale Calculator

Rate your agreement with 9 statements about fatigue using the Fatigue Severity Scale (FSS). Select your response for each item — from Strongly Disagree to Strongly Agree — and get your FSS score along with an interpretation of what it means for your daily functioning. Widely used for conditions like multiple sclerosis, lupus, fibromyalgia, and Parkinson's disease. Also try the Epworth Sleepiness Scale Calculator.

Disclaimer: This tool is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any health-related decisions.

Results

FSS Score

--

Total Points

--

Interpretation

--

Severity Level

--

Frequently Asked Questions

What is the Fatigue Severity Scale (FSS)?

The FSS is a validated 9-item self-report questionnaire that measures the severity of fatigue and its impact on daily activities. Developed by Krupp et al. in 1989, it is widely used in clinical settings for patients with multiple sclerosis, lupus, fibromyalgia, Parkinson's disease, stroke, and other chronic conditions. Each item is scored from 1 (strongly disagree) to 7 (strongly agree). See also our calculate GAD-7 Anxiety GAD-7 Total Score.

How is the FSS score calculated?

The FSS score is the average of all 9 item responses. You sum the scores for all nine questions and divide the total by 9. The result ranges from 1 to 7, with higher scores indicating greater fatigue severity and a larger negative impact on daily functioning.

What does a score of 4 or higher indicate on the FSS?

An FSS average score of 4 or above is generally considered the clinical threshold for significant fatigue. Scores at or above this level suggest that fatigue is meaningfully interfering with your daily activities and quality of life, and further evaluation by a healthcare professional is recommended.

What does a low FSS score (below 4) mean?

A score below 4 suggests that fatigue is not significantly impacting your daily life. Healthy adults without chronic conditions typically score around 2.3, reflecting minimal fatigue interference. However, individual context and clinical judgment should always be considered. You might also find our calculate Your PSS Score, Stress Level & Positive Coping Score — Stress Level useful.

Which conditions is the FSS designed for?

The FSS was originally validated for multiple sclerosis (MS) and systemic lupus erythematosus (SLE), but its use has since been extended to many other conditions including rheumatoid arthritis, fibromyalgia, Parkinson's disease, stroke, depression, and chronic fatigue syndrome.

How does the FSS compare to other fatigue scales?

Other commonly used fatigue assessment tools include the Modified Fatigue Impact Scale (MFIS), the Epworth Sleepiness Scale, the Multidimensional Fatigue Inventory (MFI), and the Chalder Fatigue Scale. The FSS stands out for its brevity, ease of use, and strong validation across multiple chronic disease populations.

Can I use this calculator to diagnose a medical condition?

No — the FSS is a screening and assessment tool, not a diagnostic instrument. The results can help you and your healthcare provider understand the extent to which fatigue affects your life, but a clinical diagnosis requires a full medical evaluation. Always consult a qualified healthcare professional for medical advice.

How often should the FSS be completed?

The FSS can be completed periodically to track changes in fatigue severity over time, especially when monitoring the effects of treatment or disease progression. Many clinicians administer it at regular follow-up appointments. There is no fixed interval — your healthcare provider will advise on the appropriate frequency for your situation.