# What is my AST/ALT ratio?

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

- Page: https://www.acalculator.org/health/ast-alt-ratio-calculator
- JSON spec: https://www.acalculator.org/health/ast-alt-ratio-calculator.json
- Version: 8081ae48d556

## Default answer

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.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| ast | AST (U/L) | Aspartate aminotransferase (AST, also called SGOT). In U/L (IU/L), 1 to 20,000. |
| alt | ALT (U/L) | Alanine aminotransferase (ALT, also called SGPT). In U/L (IU/L), 1 to 20,000. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| ratio | AST/ALT ratio | AST ÷ ALT, to 2 decimals. |
| reading | What the studies say | What the cited studies found for ratios in this range. |

## 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.

## Assumptions

- 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.

## Worked examples

1. ast = 40, alt = 20 gives ratio = 2.
2. ast = 120, alt = 50 gives ratio = 2.4, reading = 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 = 30, alt = 45 gives ratio = 0.67, reading = 1 or less: the usual finding in chronic hepatitis (Williams and Hoofnagle 1988).
4. ast = 45, alt = 45 gives ratio = 1.
5. ast = 201, alt = 100 gives ratio = 2.01, reading = Over 2: Cohen and Kaplan (1979) found this highly suggestive of alcoholic hepatitis and cirrhosis.

## FAQ

### 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.

## Sources

- Cohen JA, Kaplan MM. The SGOT/SGPT ratio: an indicator of alcoholic liver disease. Dig Dis Sci. 1979;24(11):835-838. https://doi.org/10.1007/bf01324898 (retrieved 2026-10-05)
- Williams AL, Hoofnagle JH. Ratio of serum aspartate to alanine aminotransferase in chronic hepatitis: relationship to cirrhosis. Gastroenterology. 1988;95(3):734-739. https://doi.org/10.1016/s0016-5085(88)80022-2 (retrieved 2026-10-05)
- Botros M, Sikaris KA. The De Ritis ratio: the test of time. Clin Biochem Rev. 2013;34(3):117-130. https://pmc.ncbi.nlm.nih.gov/articles/PMC3866949/ (retrieved 2026-10-05)