NAFLD Fibrosis Score Calculator

Written by Great Medico

Updated September 24, 2026 •2 min read

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One liver score rarely tells the whole story, but the arithmetic can still be useful when its scope is clear. NAFLD Fibrosis Score Calculator applies the named formula to the entered clinical variables and keeps the limitations visible.

What this calculator does

NAFLD Fibrosis Score Calculator calculates the classic NAFLD Fibrosis Score after deriving BMI from height and weight. It only uses the fields shown in this calculator; it does not silently add tests, diagnoses, symptoms, or clinical variables that are absent from the interface. NAFLD fibrosis flow derives BMI from height and weight before applying the validated formula.

How to use it

Enter or select Age, Height, Weight, Impaired fasting glucose / diabetes, AST, and the remaining displayed fields. Keep laboratory units consistent and use values from the clinical time point required by the named model. If an input is unknown, it is better to leave the calculation unresolved than to invent a value.

How the calculation works

BMI is calculated from entered height and weight, then the NAFLD Fibrosis Score uses −1.675 + 0.037×age + 0.094×BMI + 1.13×diabetes flag + 0.99×(AST/ALT) − 0.013×platelets − 0.66×albumin.

Example

Using the calculator’s prefilled demonstration values, the primary output is -1.21, labeled “NAFLD fibrosis score”; BMI is 27.68 and AST/ALT is 1. That sample is useful for checking the calculation path, but real interpretation should use verified measurements from the same clinical or study context.

How to interpret the result

Interpret the number as an older noninvasive fibrosis-risk score in people with fatty liver disease, not as a staging diagnosis. Indeterminate or high-risk results generally require another validated fibrosis assessment.

Limitations and notes

The calculator retains the older “NAFLD Fibrosis Score” nomenclature/formula. Current practice increasingly uses MASLD terminology, and FIB-4 is commonly preferred as an initial blood-based fibrosis risk tool. NFS is a risk-stratification aid, not a diagnosis of fibrosis or cirrhosis.