{
  "id": "ast-alt-ratio",
  "version": "8081ae48d556",
  "status": "published",
  "name": "AST/ALT Ratio Calculator",
  "question": "What is my AST/ALT ratio?",
  "summary": "Divides AST by ALT (the De Ritis ratio) and shows what the published studies say a ratio over 1 or over 2 suggests.",
  "category": "health",
  "subcategory": "clinical",
  "url": "https://www.acalculator.org/health/ast-alt-ratio-calculator",
  "markdown": "https://www.acalculator.org/health/ast-alt-ratio-calculator.md",
  "kind": "function",
  "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."
  ],
  "inputs": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "properties": {
      "ast": {
        "title": "AST (U/L)",
        "description": "Aspartate aminotransferase (AST, also called SGOT). In U/L (IU/L), 1 to 20,000.",
        "type": "number",
        "minimum": 1,
        "maximum": 20000
      },
      "alt": {
        "title": "ALT (U/L)",
        "description": "Alanine aminotransferase (ALT, also called SGPT). In U/L (IU/L), 1 to 20,000.",
        "type": "number",
        "minimum": 1,
        "maximum": 20000
      }
    }
  },
  "outputs": {
    "ratio": {
      "label": "AST/ALT ratio",
      "description": "AST ÷ ALT, to 2 decimals.",
      "format": "number"
    },
    "reading": {
      "label": "What the studies say",
      "description": "What the cited studies found for ratios in this range.",
      "format": "text"
    }
  },
  "defaultAnswer": {
    "inputs": {
      "ast": 40,
      "alt": 20
    },
    "outputs": {
      "ratio": 2,
      "reading": "Over 1: in nonalcoholic chronic liver disease, Williams and Hoofnagle (1988) linked this with cirrhosis"
    },
    "text": "The AST/ALT ratio is 2. Over 1: in nonalcoholic chronic liver disease, Williams and Hoofnagle (1988) linked this with cirrhosis."
  },
  "examples": [
    {
      "given": {
        "ast": 40,
        "alt": 20
      },
      "expect": {
        "ratio": 2
      },
      "source": "40 ÷ 20 = 2.00, not over 2 (hand calculation in content.mdx)"
    },
    {
      "given": {
        "ast": 120,
        "alt": 50
      },
      "expect": {
        "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) (hand calculation in content.mdx)"
    },
    {
      "given": {
        "ast": 30,
        "alt": 45
      },
      "expect": {
        "ratio": 0.67,
        "reading": "1 or less: the usual finding in chronic hepatitis (Williams and Hoofnagle 1988)"
      },
      "source": "30 ÷ 45 = 0.667, shown as 0.67 (hand calculation in content.mdx)"
    },
    {
      "given": {
        "ast": 45,
        "alt": 45
      },
      "expect": {
        "ratio": 1
      },
      "source": "45 ÷ 45 = 1.00, 1 or less (hand calculation)"
    },
    {
      "given": {
        "ast": 201,
        "alt": 100
      },
      "expect": {
        "ratio": 2.01,
        "reading": "Over 2: Cohen and Kaplan (1979) found this highly suggestive of alcoholic hepatitis and cirrhosis"
      },
      "source": "201 ÷ 100 = 2.01, over 2 (hand calculation in content.mdx)"
    }
  ],
  "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)"
  ],
  "related": [
    "fib-4"
  ],
  "changelog": [
    {
      "date": "2026-10-05",
      "note": "Published after this site's editorial review against the cited sources (no clinician review); the page notices say so."
    }
  ]
}