NAFLD Fibrosis Score Calculator
Estimate the NAFLD Fibrosis Score (NFS) using common clinical values. This tool is for adults and should support, not replace, medical evaluation.
What is the NAFLD fibrosis score?
The NAFLD Fibrosis Score is a non-invasive scoring system used to estimate the likelihood of advanced liver fibrosis in people with non-alcoholic fatty liver disease (NAFLD). NAFLD is now often grouped under newer terminology like MASLD, but the NAFLD score remains widely referenced in clinical practice and research.
Instead of relying immediately on a liver biopsy, this score combines routine clinical and lab data to stratify risk into low, indeterminate, or high probability categories.
Formula used in this calculator
This calculator uses the original NFS equation:
Where IFG/Diabetes is coded as 1 if present and 0 if absent.
How to interpret results
- NFS < -1.455: Low probability of advanced fibrosis.
- NFS between -1.455 and 0.676: Indeterminate zone (additional evaluation often needed).
- NFS > 0.676: High probability of advanced fibrosis.
These thresholds are useful for triage and risk stratification. Final diagnosis should always be made by a qualified clinician with full clinical context.
How to use this calculator correctly
1) Check units first
- Age in years
- BMI in kg/m²
- AST and ALT in U/L
- Platelets in ×10⁹/L
- Albumin in g/dL
2) Use current laboratory values
If labs are old or from different clinical states (for example, acute illness), the score may not reflect your baseline liver risk.
3) Combine with clinical judgment
In indeterminate cases, clinicians often consider additional tools such as FIB-4, elastography, imaging, and hepatology referral.
Important limitations
- Not designed as a standalone diagnostic test.
- Performance varies by population and care setting.
- Acute inflammation, alcohol use, medications, and comorbid illness may affect liver enzymes and score interpretation.
- Should not be used as emergency guidance.
FAQ
Is a high score a diagnosis of cirrhosis?
No. A high score suggests increased probability of advanced fibrosis, not a definitive diagnosis.
What if the result is indeterminate?
That is common. Indeterminate results typically require additional non-invasive testing and clinician follow-up.
Can I use this for children?
This tool is intended for adults and is not validated for pediatric use.
Clinical reminder
This NAFLD score calculator is educational and informational. Always discuss results with your healthcare professional, especially if you have abnormal liver tests, diabetes, obesity, metabolic syndrome, or other chronic conditions.