acalculator

What is my AST/ALT ratio?

Enter AST and ALT from a liver panel to get the AST/ALT (De Ritis) ratio and what the published studies say about it. For information only. This is not medical advice or a diagnosis. Do not use it to make treatment decisions without a clinician. No licensed clinician has reviewed this page.

Your numbers

AST/ALT ratio
2

The AST/ALT ratio is 2. Over 1: in nonalcoholic chronic liver disease, Williams and Hoofnagle (1988) linked this with cirrhosis.

Over 1, up to 2

  1. 1 or less
  2. Over 1, up to 2
  3. Over 2
What the studies say
Over 1: in nonalcoholic chronic liver disease, Williams and Hoofnagle (1988) linked this with cirrhosis

AST/ALT ratio: 2. The AST/ALT ratio is 2. Over 1: in nonalcoholic chronic liver disease, Williams and Hoofnagle (1988) linked this with cirrhosis.

Where does the ratio sit?

This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use

How to calculate

Divides AST by ALT (the De Ritis ratio) and shows what the published studies say a ratio over 1 or over 2 suggests.

Example with the default inputs (AST (U/L) 40, ALT (U/L) 20): The AST/ALT ratio is 2. Over 1: in nonalcoholic chronic liver disease, Williams and Hoofnagle (1988) linked this with cirrhosis.

Method: AST/ALT ratio = AST ÷ ALT (same units), to 2 decimals. Over 2: Cohen and Kaplan 1979. Over 1 in nonalcoholic chronic liver disease: Williams and Hoofnagle 1988.

  • AST and ALT come from the same blood sample and are in the same units (U/L or µkat/L).
  • The ratio is rounded once to 2 decimals, halves up, and the shown value is compared with 1 and 2.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. AST (U/L) 40, ALT (U/L) 20 gives AST/ALT ratio 2.
  2. AST (U/L) 120, ALT (U/L) 50 gives AST/ALT ratio 2.4, What the studies say Over 2: Cohen and Kaplan (1979) found this highly suggestive of alcoholic hepatitis and cirrhosis.Source: 120 ÷ 50 = 2.40, over 2 (Cohen and Kaplan 1979)
  3. AST (U/L) 30, ALT (U/L) 45 gives AST/ALT ratio 0.67, What the studies say 1 or less: the usual finding in chronic hepatitis (Williams and Hoofnagle 1988).
  4. AST (U/L) 45, ALT (U/L) 45 gives AST/ALT ratio 1.
  5. AST (U/L) 201, ALT (U/L) 100 gives AST/ALT ratio 2.01, What the studies say Over 2: Cohen and Kaplan (1979) found this highly suggestive of alcoholic hepatitis and cirrhosis.

Medical disclaimer

This calculator is for information and education only. It is not medical advice, and its result is not a diagnosis. Do not use it to start, stop, or change a treatment without a clinician who knows your health history. No licensed clinician has reviewed this page. This site's editors checked the formulas and worked examples against published sources. If you think you have a medical emergency, call your local emergency number.

When this does not apply. The cited studies looked at adults with known liver disease. The ratio changes over the course of an illness, because AST clears from the blood faster than ALT (Botros and Sikaris 2013). Lab methods also differ (for example, whether the assay adds pyridoxal phosphate), so compare ratios from the same lab.

How it works

  1. AST/ALT ratio = AST ÷ ALT, both in U/L (IU/L), from 1 to 20,000.
  2. The page divides the exact typed values and rounds once to 2 decimals, halves up.
  3. The shown ratio is read against two published cut-offs:
    • Over 2: Cohen and Kaplan (1979) found this highly suggestive of alcoholic hepatitis and cirrhosis.
    • Over 1, up to 2: in nonalcoholic chronic liver disease, Williams and Hoofnagle (1988) linked a ratio over 1 with cirrhosis.
    • 1 or less: the usual finding in chronic hepatitis (Williams and Hoofnagle 1988).

Worked examples by hand

Page default. AST 40, ALT 20. 40 ÷ 20 = 2.00, not over 2, so over 1, up to 2.

Over 2. AST 120, ALT 50. 120 ÷ 50 = 2.40, over 2.

Under 1. AST 30, ALT 45. 30 ÷ 45 = 0.6667, 0.67, 1 or less.

Exactly 1. AST 45, ALT 45. 1.00, 1 or less.

Just over 2. AST 201, ALT 100. 201 ÷ 100 = 2.01, over 2.

Other questions people ask

How do I calculate the AST/ALT ratio?

Divide AST by ALT, both in the same units. AST 40 U/L and ALT 20 U/L give 40 ÷ 20 = 2.0. The ratio is the same in µkat/L.

What does an AST/ALT ratio over 2 mean?

Cohen and Kaplan (1979) found a ratio over 2 highly suggestive of alcoholic hepatitis and cirrhosis: it occurred in 70% of those patients and much less often in other liver diseases.

What does a ratio over 1 mean?

Williams and Hoofnagle (1988) studied people with nonalcoholic chronic liver disease. The ratio was usually under 1 in chronic viral hepatitis and often rose above 1 when cirrhosis developed.

What is the De Ritis ratio?

Another name for the AST/ALT ratio, after Fernando De Ritis, who described it in 1957 in viral hepatitis.

Is a normal ratio a sign that my liver is healthy?

No. The ratio says nothing about how high AST and ALT are. Two very high values can still give a ratio of 1. Read it with the separate values and with a clinician.

Why does the page round before it compares?

The page shows the ratio to 2 decimals and compares that value with 1 and 2, so the text always matches the number you see. A ratio of 2.004 shows as 2 and is not over 2.