NAFLD Fibrosis Score

Non-invasive score used to estimate advanced fibrosis in patients with NAFLD/MASLD.

Gastroenterology GastroenterologyEvidence-BasedUpdated 2026-07

Clinical Notes

Formula

-1.675 + (0.037×Age) + (0.094×BMI) + (1.13×Diabetes) + (0.99×AST/ALT) − (0.013×Platelets) − (0.66×Albumin)

Clinical Notes

The NAFLD Fibrosis Score helps identify patients at low or high risk of advanced fibrosis without liver biopsy.

References

Angulo P, Hepatology. 2007.
AASLD Practice Guidance.
EASL Clinical Practice Guidelines.

Calculator Information

Specialty

Gastroenterology

📋 Reference Ranges

Reference ranges for this calculator
Classification	Range
Low Probability	< -1.455
Indeterminate	-1.455 to 0.676
High Probability	> 0.676

What This Calculator Measures

Calculates the NAFLD Fibrosis Score to estimate the probability of advanced fibrosis non-invasively in patients with NAFLD/MASLD.

How to Use

Enter age, BMI, diabetes/impaired fasting glucose status, AST, ALT, platelet count, and albumin.
Confirm the patient has a diagnosis of NAFLD/MASLD before applying the score.
Interpret the result against the −1.455 and 0.676 thresholds.

Interpretation Guide

NFS <−1.455 indicates low probability of advanced fibrosis; −1.455 to 0.676 is indeterminate; >0.676 indicates high probability of advanced fibrosis.

Age-specific interpretation

Clinical Significance

The NAFLD Fibrosis Score is an AASLD-endorsed, non-invasive tool that helps identify patients with NAFLD/MASLD at risk of advanced fibrosis, reducing unnecessary biopsies.

When to Use

Risk-stratifying patients with NAFLD/MASLD in primary care
Triaging which patients need hepatology referral
Estimating advanced fibrosis risk when elastography is not available

When Not to Use

Liver disease other than NAFLD/MASLD
Acute liver injury with unstable transaminases
Children and adolescents
To stage fibrosis when indeterminate — confirm with elastography or biopsy

Limitations

Accuracy is limited in the indeterminate band, which requires further evaluation.
The diabetes/IFG input is binary and does not capture glycemic detail.
Requires albumin measurement and is best validated in NAFLD cohorts.

Worked Example

A 58-year-old man with MASLD and type 2 diabetes has BMI 32 kg/m², AST 60 U/L, ALT 40 U/L, platelets 180 ×10⁹/L, and albumin 3.8 g/dL.

Inputs:

age: 58

bmi: 32

diabetes: 1

ast: 60

alt: 40

platelets: 180

albumin: 3.8

NFS = −1.675 + 0.037(58) + 0.094(32) + 1.13(1) + 0.99(60/40) − 0.013(180) − 0.66(3.8) ≈ 1.246 — high probability of advanced fibrosis (>0.676).

Evidence

Source: Hepatology Literature
Reference: Angulo P, et al. The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD. Hepatology. 2007;45:846-854.
Reviewed By: MedCalcHub Clinical Team
Version: 1.0
Updated: 2026-08

Angulo P, et al. Hepatology. 2007;45:846-854.

References

Angulo P, et al. The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD. Hepatology. 2007;45:846-854. (Original score)

Disclaimer: This calculator is intended for educational and clinical decision support. The NAFLD Fibrosis Score is a screening tool and does not replace clinical evaluation or confirmatory fibrosis testing.