AST to Platelet Ratio Index (APRI) Calculator

AST to Platelet Ratio Index (APRI) Calculator

APRI Calculator


APRI ScoreInterpretationAPRI Threshold
<0.5Minimal or no fibrosis0.7 ( Significant fibrosis )
0.5 - 1.5Moderate fibrosis or significant fibrosis1.0 ( Severe fibrosis )
>1.5Severe fibrosis or cirrhosis1.0 ( Cirrhosis )

Consult Your Doctors for Further Investigation

APRI calculator is used to calculating APRI score for assessing liver fibrosis and can be an effective way to monitor liver disease.


APRI Calculator Overview

  • The APRI Calculator or AST to Platelet Ratio Index Calculator is a powerful tool designed to help medical professionals assess liver fibrosis in patients with chronic hepatitis C.
  • The APRI Calculator uses two routine blood tests, AST (Aspartate Aminotransferase) and platelet count, to estimate liver fibrosis and cirrhosis.
  • Using our APRI Calculator, medical professionals can easily and quickly calculate the APRI score, which is a non-invasive way to assess liver damage in patients with hepatitis C.
  • The APRI score is a reliable indicator of liver fibrosis, with higher scores indicating more advanced liver disease.


How To Calculate APRI Score

Here are steps to calculate APRI Score using the above calculator.

  • Enter AST Level in IU/liter
  • Enter ALT Upper Limit in IU/liter
  • Enter Platelet Count
  • Calculate APRI Score


APRI Score Formula

Here is a basic formula for calculating APRI Score.

APRI = [ (AST level / AST upper limit) / Platelet count ] × 100


  • AST level - the aspartate aminotransferase level of the patient, expressed in IU/L (international units per litre);
  • AST upper limit - a value used to make the calculations more specific.
  • Platelet count - the patient's platelet count, expressed in 10⁹/L.


Normal Range Of Parameter For Healthy Person

  • AST Level :  15 - 41 IU/liter 
  • AST Upper Limit : 15 - 41 IU/liter
  • Platelet Count Range: 150 - 350  

* Adding more value than this give unexpected result, prefer your lab report or doctor to know exact values.


APRI Score Normal Range

Here is the normal range of the APRI Score.

APRI Score Interpretation Likelihood of Fibrosis
< 0.5 Minimal or no fibrosis Low
0.5 - 1.5 Moderate fibrosis or significant fibrosis Intermediate
> 1.5 Severe fibrosis or cirrhosis High


APRI Score Normal Range and Interpretation


APRI Score Interpretation

Here is the APRI score interpretation.

APRI Score Interpretation APRI Threshold
< 0.5 Minimal or no fibrosis 0.7 ( Significant fibrosis )
0.5 - 1.5 Moderate fibrosis or significant fibrosis 1.0 ( Severe fibrosis )
> 1.5 Severe fibrosis or cirrhosis 1.0 ( Cirrhosis )


High APRI Score

  • A high APRI score suggests that there may be significant liver fibrosis or scarring.
  • A score of 1.5 or greater indicates a high likelihood of significant liver fibrosis, while a score less than 0.5 suggests minimal or no fibrosis.
  • It's important to note that a high APRI score alone is not sufficient to diagnose liver fibrosis or any liver disease.
  • Additional tests, such as a liver biopsy, may be required for a definitive diagnosis.
  • The APRI score should be interpreted in conjunction with other clinical and laboratory findings to make an accurate diagnosis and determine the appropriate course of treatment.


Calculating APRI Score

Let's calculate the APRI score of a patient with the following laboratory tests:

  • AST level - 120 IU/L;
  • AST upper limit - 40 IU/L; and
  • platelet count - 100 × 10⁹/L.


APRI = [(AST level / AST upper limit) / Platelet count] × 100

APRI = [(120 / 40) / 100] × 100

APRI = [3 / 100] × 100

APRI = 0.030 × 100

APRI = 3


APRI Calculator Benefits

The benefits of using an APRI calculator include:

  1. Non-invasive: An APRI calculator is a non-invasive tool that does not require a liver biopsy, which is a more invasive procedure that carries some risk.
  2. Cost-effective: An APRI calculator is a cost-effective way to assess liver fibrosis compared to a liver biopsy, which can be expensive.
  3. Rapid Results: An APRI calculator provides rapid results that can be obtained within minutes, which can be helpful for making decisions about treatment options.
  4. Widely Available: An APRI calculator is widely available and can be performed in most medical laboratories.
  5. Early Diagnosis: An APRI calculator can help in the early diagnosis of liver fibrosis, which can lead to better treatment outcomes.



Overall, an APRI calculator is a useful tool for assessing liver fibrosis and can be an effective way to monitor liver disease progression and guide treatment decisions. Check More Medical Health Related Calculator on Drlogy Calculator to get exact health solutions.



  • AST to platelet ratio index (APRI) for the noninvasive evaluation of liver fibrosis [1].
  • Using AST-platelet ratio index and fibrosis 4 index for detecting chronic hepatitis C in a large-scale community screening [2].
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