FIB-4 Index Calculator

A validated non-invasive score used to decide whether liver fibrosis is unlikely enough to stop looking, or needs a specialist test.

years
U/L
U/L
K/µL
Your FIB-4 Index

Reference bands

ResultBand
Under 1.30Advanced fibrosis unlikely
1.30 to 2.67Indeterminate, further testing usual
Above 2.67Advanced fibrosis more likely

FIB-4 = (age × AST) ÷ (platelets × √ALT). ⚠️ The 1.30 threshold is less reliable above age 65, where 2.0 is often used instead.

One number is one line of your test.

BloodMarker reads your whole panel and tells you what the lines say together, which is the part no single calculation can do.

Your values carry over · PDF or a photo · about 8 seconds

Questions

What is the FIB-4 index?

It is a score combining age, two liver enzymes and platelet count, used as a first-line non-invasive check for advanced liver fibrosis.

What does a low FIB-4 mean?

A score under 1.30 makes advanced fibrosis unlikely and is often used to rule it out without further imaging. It is not a guarantee.

Other calculators

Not medical advice. These calculators are for information only. Reference bands differ between laboratories and none of these numbers can be interpreted without your history, your other results and a clinician. Nothing you type here is sent to us or stored on a server.