FIB-4 Index · AASLD 2023 · EASL 2024

FIB-4 Liver Fibrosis Index

Calculates FIB-4 from age, AST, ALT and platelets and maps it to the AASLD 2023 / EASL 2024 cut-offs to decide whether liver stiffness testing is needed.

What this tool does

Estimate liver fibrosis risk (FIB-4) from age, AST, ALT and platelets.

What you need

AST and ALT from your liver panel and platelets from your blood count.

What the result means

Low/intermediate/high risk with age-adjusted cut-offs; FIB-4 is a screening tool, not a diagnosis.

Enter the values above

Kidney patients: platelets may be low in CKD, which inflates FIB-4; azathioprine/mycophenolate after transplant can also lower platelets. Interpret with hepatology rather than on the number alone.

Privacy: all calculations run on your device; no values are sent to a server or third party. Log-type tools store data only in your browser (localStorage); clearing browsing data removes it.

This is not a diagnosis. It maps the numbers you entered onto published guideline categories; a real assessment needs a clinician, your history, repeat testing and other investigations.

Scope and limitations

  • FIB-4 was developed in HIV/HCV co-infection (Sterling 2006) and later validated in MASLD; cut-offs may differ in alcohol-related liver disease, hepatitis B and autoimmune hepatitis.
  • Unreliable in acute hepatitis (ALT in the hundreds or more), biliary obstruction, or thrombocytopenia from other causes (ITP, splenomegaly, drugs).
  • FIB-4 is a rule-out tool (high negative predictive value), not a rule-in tool (positive predictive value ≈60–65%).
  • It cannot determine the cause of fatty liver or detect liver cancer.

Formula & cut-off sources

  1. Sterling RK, et al. Development of a simple noninvasive index to predict significant fibrosis (FIB-4). Hepatology 2006;43:1317–1325
  2. Rinella ME, et al. AASLD Practice Guidance on NAFLD/MASLD. Hepatology 2023;77:1797–1835
  3. EASL–EASD–EASO Clinical Practice Guidelines on MASLD. J Hepatol 2024;81:492–542

To discuss with your doctor

  1. What is my FIB-4? Do I need a FibroScan?
  2. Do I have fatty liver — is it MASLD?
  3. Is my low platelet count due to kidney disease or medication?
  4. Should I be screened for liver cancer?

Next step

After this result, people usually continue with: