NAFLD Fibrosis Score Calculator
Calculate the NAFLD Fibrosis Score (NFS) to identify patients with non-alcoholic fatty liver disease at risk of advanced fibrosis.
What is NAFLD Fibrosis Score?
The NAFLD Fibrosis Score (NFS), developed by Angulo et al. in 2007, uses six readily available variables (age, BMI, glucose status, AST, ALT, platelets, albumin) to estimate the probability of advanced liver fibrosis (F3–F4) in patients with non-alcoholic fatty liver disease. It performs well as a non-invasive triage tool — a low NFS rules out advanced fibrosis with a high negative predictive value, sparing many patients unnecessary biopsies.
How is it calculated?
NFS = −1.675 + 0.037 × age + 0.094 × BMI + 1.13 × (IFG / diabetes 1, otherwise 0) + 0.99 × (AST/ALT) − 0.013 × platelets − 0.66 × albumin. Cut-offs: < −1.455 advanced fibrosis unlikely; −1.455 to 0.676 indeterminate; > 0.676 advanced fibrosis likely.
Frequently Asked Questions
- How accurate is NFS?
- High negative predictive value — useful for ruling out advanced fibrosis.
- Should I combine NFS with other scores?
- Yes — FIB-4 is commonly used alongside.
- Does NFS work in non-NAFLD?
- No — it was developed and validated specifically for NAFLD.
- What if NFS is indeterminate?
- Pursue transient elastography (FibroScan) or specialist referral.