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AST/ALT Ratio (De Ritis Ratio)

The ratio of AST to ALT.

For healthcare professionalsLiverv1.0.1

For healthcare professionals / clinical use. Not a self-diagnosis tool.

Your measurements

U/L
U/L

Calculated on your device. Nothing is sent to a server.

Your result will appear here

Enter your measurements, then press Calculate.

Methodology

De Ritis ratio

AST ÷ ALT

A ratio above 2 is classically associated with alcohol-related liver disease and a rising ratio with advancing fibrosis, but the ratio is not diagnostic on its own. Interpretation depends on timing: acute viral hepatitis can have AST above ALT, and alcoholic hepatitis can have ALT above AST after several days without alcohol (Botros 2013).

Who it is for
Adults with abnormal liver enzymes.
Version
1.0.1

How this calculator works

Where the formula comes from

  • De Ritis described the AST/ALT ratio almost 50 years before a 2013 review; it was first described in acute viral hepatitis, where ALT is usually higher than AST.[1]

The inputs

  • The ratio partly reflects the shorter half-life of AST (about 18 hours) compared with ALT (about 36 hours).[1]

Versions and alternatives

  • In 139 patients with chronic hepatitis C, a ratio of 1 or more had 100% specificity and 53.2% sensitivity for cirrhosis.[2]
  • In chronic viral hepatitis, chronic alcohol use and non-alcoholic fatty liver disease, an elevated AST/ALT ratio has been associated with long-term complications, including fibrosis and cirrhosis.[1]

Where accuracy falls (published evidence)

  • Simple interpretations can mislead: acute viral hepatitis can have AST above ALT, and alcoholic hepatitis can have ALT above AST several days after alcohol exposure.[1]

Sources

  1. Botros M, Sikaris KA. The De Ritis ratio: the test of time. Clin Biochem Rev. 2013;34(3):117–130. PMID 24353357
  2. Sheth SG, Flamm SL, Gordon FD, Chopra S. AST/ALT ratio predicts cirrhosis in patients with chronic hepatitis C virus infection. Am J Gastroenterol. 1998;93(1):44–48. doi:10.1111/j.1572-0241.1998.044_c.x

Compiled from the published sources above. Every statement was agreed independently by three AI research tools (Claude, ChatGPT, DeepSeek) and its source verified in PubMed or Crossref by the Hakeemly editorial team. Not reviewed by a doctor unless stated. Agreed on

Worked example: how to calculate AST/ALT ratio

Inputs

AST
120 U/L
ALT
50 U/L

Result

AST/ALT
2.4

Calculation:

120/50 = 2.4

An illustration with sample values, worked out with the same method the tool above uses.

Limitations

  • Muscle injury, haemolysis and macro-AST raise AST independently of the liver.

References

  1. Botros M, Sikaris KA. The De Ritis ratio: the test of time. Clin Biochem Rev. 2013;34(3):117–130.

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