Calculator · Gastro / hepatology

FIB-4 (liver fibrosis)

Non-invasive fibrosis estimate in MASLD / chronic liver disease.

What it is for

Fibrosis estimate in MASLD / chronic liver disease. NICE NG49 and the BSG describe what follows each band.

Use the working calculator

The working FIB-4 (liver fibrosis) calculator is on our calculators page. It is free and needs no account. Enter the values and it shows the result with the reading that goes with it.

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What you enter

The calculator asks for 4 items.

  • Age (yrs)
  • AST (U/L)
  • ALT (U/L)
  • Platelets (×10⁹/L)

How the result is read

The result is shown as FIB-4. Formula: (age × AST) / (platelets ×10⁹/L × √ALT)

The calculator reports one of these readings, with the action that goes with it: Low risk advanced fibrosis; Indeterminate; High risk advanced fibrosis.

Sources

These are the sources the calculator cites. Check the current version before relying on a threshold.

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For qualified clinicians. A score supports a clinical decision and does not make it: check the inputs, read the cited source, and use the tools in your clinical system for patient care where one is provided.