FIB-4 Calculator

Estimate the amount of scarring in the liver based on medical lab results.

Enter Patient Data

Note: Platelet count should be in 10^9/L (same as 10^3/µL or 10^3/mm^3).
Calculated FIB-4 Score:
0.00

About the FIB-4 Index

The Fibrosis-4 (FIB-4) index is a simple, non-invasive scoring system used to estimate the degree of fibrosis in the liver. It helps in assessing patients with liver conditions (e.g., NAFLD/MASH, Hepatitis C, Hepatitis B) to identify those with varying probabilities of advanced fibrosis or cirrhosis.

Formula
FIB-4 = (Age × AST) / (Platelet Count × √ALT)
Interpretation Criteria
FIB-4 Score Fibrosis Risk Recommendation
< 1.45
(or < 2.0 if age ≥ 65)		 Low Risk High negative predictive value for ruling out advanced fibrosis.
1.45 - 3.25 Indeterminate May require further testing, such as transient elastography or liver biopsy.
> 3.25 High Risk High positive predictive value for ruling in advanced fibrosis/cirrhosis.