What is a normal APRI score?

An APRI score below 0.5 makes significant fibrosis unlikely. Scores between 0.5 and 1.5 are considered indeterminate and may warrant further testing. Scores above 1.5 suggest significant fibrosis is likely.

What APRI score indicates cirrhosis?

An APRI score below 1.0 makes cirrhosis unlikely, while a score above 2.0 suggests cirrhosis is likely. Scores between 1.0 and 2.0 are indeterminate for cirrhosis.

What is the standard AST upper limit of normal?

The most commonly used AST upper limit of normal (ULN) is 40 U/L. However, laboratory reference ranges vary. Always use the ULN from the patient's own laboratory report for the most accurate result.

Can APRI replace a liver biopsy?

No. APRI is a non-invasive screening tool and cannot definitively diagnose the degree of fibrosis. A liver biopsy remains the gold standard. APRI helps identify patients who are unlikely to have significant disease and may not require biopsy.

Is this calculator suitable for all liver diseases?

APRI was originally validated in patients with chronic hepatitis C and has been studied in hepatitis B and NAFLD. Its performance may vary in other liver conditions. Always consult a hepatologist for clinical decision-making.

What platelet unit should I use?

Enter the platelet count in 10⁹/L (also written as ×10³/µL or 10³ cells/µL). For example, if the lab report says 150,000/µL or 150 × 10³/µL, enter 150.

APRI Score Calculator

Name: APRI Score Calculator
Availability: InStock
Author: Nham Vu

Enter AST and platelet count to calculate the APRI score and assess likelihood of liver fibrosis or cirrhosis.

Lab Values

Enter the patient's laboratory results below.

AST Level (U/L)

Serum aspartate aminotransferase (AST)

AST Upper Limit of Normal (U/L)

Laboratory reference ULN — default is 40 U/L

Platelet Count (10⁹/L)

e.g. enter 150 for 150 × 10⁹/L (150,000/µL)

Enter lab values and click Calculate to see the APRI score.

Results include fibrosis and cirrhosis interpretation.

Interpretation Reference

APRI Range	Fibrosis	Cirrhosis
< 0.5	Unlikely	—
0.5 – 1.0	Indeterminate	Unlikely
1.0 – 1.5	Indeterminate	Indeterminate
1.5 – 2.0	Likely	Indeterminate
> 2.0	Likely	Likely

Medical Disclaimer: This tool is for educational reference only. APRI scores are not a substitute for professional medical diagnosis or liver biopsy. Always consult a qualified healthcare provider for clinical decision-making. Results should be interpreted in the context of the patient's full clinical picture.

Summary

Enter AST and platelet count to calculate the APRI score and assess likelihood of liver fibrosis or cirrhosis.

How it works

Enter the patient's serum AST level in U/L.
Enter or confirm the AST upper limit of normal (ULN) for your laboratory (default 40 U/L).
Enter the platelet count in units of 10⁹/L (e.g., 150 for 150,000 platelets/µL).
The calculator applies the formula: APRI = (AST / AST_ULN) / Platelet × 100.
Review the score and its interpretation for fibrosis and cirrhosis likelihood.

Use cases

Screening patients with chronic hepatitis C for significant fibrosis before biopsy.
Monitoring liver disease progression in patients with non-alcoholic fatty liver disease.
Assessing cirrhosis risk in patients with chronic hepatitis B.
Guiding decisions on whether a liver biopsy is warranted.
Evaluating treatment response in chronic liver disease management.
Teaching clinical scoring systems in medical education settings.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu