What is a normal APRI score?

There is no normal range, only cut-offs. 0.5 or below means significant scarring is unlikely; above 1.5 means it is likely. Above 2.0 points to cirrhosis (advanced scarring) in the World Health Organization’s hepatitis B guideline.

How do you calculate APRI?

Divide AST by the upper limit of normal for AST (from your report), multiply by 100 and divide by your platelet count in ×10⁹/L. AST 60, upper limit 40 and platelets 210 give (60 ÷ 40) × 100 ÷ 210 = 0.71.

APRI or FIB-4: which is better?

For fatty liver disease, guidelines prefer FIB-4. APRI was built for hepatitis C and is widely used where scans are scarce. Both are first checks; a FibroScan or a specialist settles an unclear result.

APRI calculator (AST to platelet ratio index)

Short answer: APRI estimates liver scarring from AST and platelets: (AST ÷ the upper limit of AST) × 100 ÷ platelets. At 0.5 or below, significant fibrosis is unlikely; above 1.5 it is likely; above 2.0 the World Health Organization uses it as a sign of cirrhosis in hepatitis B.

Free calculator

APRI calculator (AST to platelet ratio)

APRI = (AST ÷ AST upper limit) × 100 ÷ platelets

Sources: Wai CT, Greenson JK, Fontana RJ, et al. A simple noninvasive index can predict both significant fibrosis and cirrhosis in patients with chronic hepatitis C. Hepatology 2003;38(2):518-526.

AST (also called SGOT)

U/L

In U/L

Upper limit of AST on your report(optional)

U/L

The top of the range printed next to AST. Leave empty to use 40 U/L

Platelets

×10⁹/L

×10⁹/L is the same number as ×10³/µL or K/µL

Your result

Enter the numbers from your lab report to see your result.

APRI was built for chronic hepatitis C and is also used in hepatitis B. It is a first check, not a diagnosis.

Worked out in your browser. Nothing you type is sent or saved.

A pointer, not a diagnosis. Talk to a doctor about your result, and sooner if you feel unwell.

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How to read the result

Low (0.5 or below)< 0.5Significant liver scarring is unlikely.
In between (0.5 to 1.5)0.5 – 1.5Not clear either way. A doctor may suggest a second test, such as a FibroScan, to settle it.
High (above 1.5)≥ 1.5Significant liver scarring is likely. This needs a doctor, who will usually arrange a FibroScan or refer you to a liver specialist.

Your lab’s range

APRI is not printed on most lab reports and has no normal range, only the cut-offs above. AST is read against the upper limit your own lab prints (often 35–40 U/L), which is why the calculator asks for it.

How it is worked out

APRI = (AST ÷ AST upper limit) × 100 ÷ platelets

APRI was built for chronic hepatitis C and is also used in hepatitis B. It is a first check, not a diagnosis.

Sources

Wai CT, Greenson JK, Fontana RJ, et al. A simple noninvasive index can predict both significant fibrosis and cirrhosis in patients with chronic hepatitis C. Hepatology 2003;38(2):518-526.
World Health Organization. Guidelines for the prevention, care and treatment of persons with chronic hepatitis B infection. Geneva: WHO; 2015.

The markers it uses

SGOT (AST)Platelet Count

Questions

What is a normal APRI score?: There is no normal range, only cut-offs. 0.5 or below means significant scarring is unlikely; above 1.5 means it is likely. Above 2.0 points to cirrhosis (advanced scarring) in the World Health Organization’s hepatitis B guideline.
How do you calculate APRI?: Divide AST by the upper limit of normal for AST (from your report), multiply by 100 and divide by your platelet count in ×10⁹/L. AST 60, upper limit 40 and platelets 210 give (60 ÷ 40) × 100 ÷ 210 = 0.71.
APRI or FIB-4: which is better?: For fatty liver disease, guidelines prefer FIB-4. APRI was built for hepatitis C and is widely used where scans are scarce. Both are first checks; a FibroScan or a specialist settles an unclear result.

More calculators for the same system

FIB-4 calculator (liver fibrosis)De Ritis ratio calculator (AST/ALT)Albumin/globulin (A/G) ratio calculator

All blood test calculators

A pointer, not a diagnosis. Talk to a doctor about your result, and sooner if you feel unwell. Reference ranges are general-population guidance compiled from common clinical laboratories, not a diagnosis. Lab-to-lab ranges differ. Always read your results with your doctor.