# AST/ALT Ratio Calculator Calculate the AST/ALT ratio (De Ritis ratio) for liver disease differential diagnosis. Helps distinguish alcoholic from non-alcoholic liver conditions. ## What this calculates The AST/ALT ratio, also known as the De Ritis ratio, is a simple calculation that helps clinicians differentiate between types of liver disease. A ratio above 2 strongly suggests alcoholic liver disease, while a ratio below 1 points toward non-alcoholic causes. Enter your AST and ALT values to calculate your ratio. ## Inputs - **AST (Aspartate Aminotransferase)** (U/L) — min 1, max 10000 — Also called SGOT. Normal range is typically 10-40 U/L. - **ALT (Alanine Aminotransferase)** (U/L) — min 1, max 10000 — Also called SGPT. Normal range is typically 7-56 U/L. ## Outputs - **AST/ALT Ratio (De Ritis Ratio)** — The ratio of AST to ALT values - **Interpretation** — formatted as text — Clinical significance of the AST/ALT ratio - **Enzyme Elevation** — formatted as text — Whether AST and ALT levels are within normal range ## Details AST (aspartate aminotransferase, formerly SGOT) and ALT (alanine aminotransferase, formerly SGPT) are enzymes released into the blood when liver cells are damaged. While both are markers of liver injury, their ratio provides diagnostic clues because they have different tissue distributions and release patterns. ALT is found primarily in the liver and is considered more specific for liver damage. AST is found in the liver, heart, muscle, kidneys, and brain. In most acute liver injuries (like viral hepatitis), ALT rises higher than AST, giving a ratio below 1.0. **Clinical patterns by ratio:** - **Ratio 2.0:** Strongly suggestive of alcoholic hepatitis (classic pattern: AST usually 2, GGT elevated) As chronic liver disease of any cause progresses to cirrhosis, the ratio tends to rise above 1.0. This happens because damaged hepatocytes release less ALT over time (ALT has a shorter half-life), and mitochondrial AST release increases with worsening cellular damage. The De Ritis ratio was first described by Italian physician Fernando De Ritis in 1957. It remains a useful bedside tool, though it should always be interpreted alongside other liver tests (alkaline phosphatase, GGT, bilirubin, albumin), imaging, and clinical history. ## Frequently Asked Questions **Q: What is a normal AST/ALT ratio?** A: In healthy individuals, the AST/ALT ratio is typically around 0.8. Most non-alcoholic liver conditions have a ratio below 1.0. A ratio above 1.0 can indicate more advanced liver disease or alcoholic liver disease, and a ratio above 2.0 is strongly associated with alcoholic hepatitis. **Q: Can the AST/ALT ratio diagnose liver disease by itself?** A: No. The ratio is one piece of the diagnostic puzzle. It helps point clinicians in the right direction, but a complete evaluation requires additional blood tests (hepatitis panel, GGT, alkaline phosphatase, bilirubin, albumin, INR), liver imaging (ultrasound, CT, or MRI), and sometimes a liver biopsy. Clinical history, especially alcohol use and medications, is equally important. **Q: Why does the ratio rise in cirrhosis?** A: As chronic liver disease progresses to cirrhosis, the ratio increases because of two factors. First, severely damaged hepatocytes release more mitochondrial AST (which is the primary AST isoform in the liver). Second, ALT production decreases as functional liver mass declines. The net result is that AST becomes proportionally higher than ALT, pushing the ratio above 1.0 regardless of the original cause of liver disease. **Q: What if my AST and ALT are both normal?** A: If both values are within normal range, the ratio is less clinically significant. Normal AST is typically 10 to 40 U/L and normal ALT is typically 7 to 56 U/L, though reference ranges vary by laboratory. Even with normal levels, the ratio can be informative in certain contexts, but most clinical relevance applies when one or both enzymes are elevated. --- Source: https://vastcalc.com/calculators/health/ast-alt-ratio Category: Health & Fitness Last updated: 2026-04-08