How do I calculate the De Ritis ratio?

Divide AST by ALT (both in U/L). The calculator does it instantly — enter the values from a blood chemistry panel.

What is a normal De Ritis ratio?

The typical range is about 0.8–1.33. Below 0.8 points to hepatocellular injury, above 1.33 to a cardiac/muscle source or progression, 2 and above to alcoholic injury or cirrhosis.

What does a ratio above 2 mean?

An AST/ALT ratio of 2 and above is classically linked to alcoholic liver disease and cirrhosis. It’s a guide that needs a doctor’s assessment alongside other tests.

Ratio is normal but ALT/AST are high — what does that mean?

The ratio is only one detail. Elevated enzymes themselves warrant attention and a doctor’s work-up of the cause, regardless of the ratio.

De Ritis ratio (AST/ALT)

Enter your AST and ALT from a blood chemistry panel — the calculator computes the De Ritis ratio (AST/ALT) and shows which way the balance is shifted. It helps orient the character of liver or muscle injury, especially when enzymes are elevated.

Compute the De Ritis ratio

Enter AST and ALT — the ratio appears instantly.

What the De Ritis ratio means

Interpretation guides. The ratio is informative mainly when AST and ALT are elevated.

AST/ALT	What it suggests
below 0.8	Shift to ALT: hepatitis, NAFLD
0.8–1.33	Typical range
1.33–2	Shift to AST: cardiac/muscle, progression
2 and above	Alcoholic injury, cirrhosis

What the De Ritis ratio is

The De Ritis ratio is the ratio of two enzymes, AST to ALT. Both leak into the blood when cells are damaged, but ALT is more liver-specific while AST is also found in heart, muscle and red cells. So their ratio helps suggest where the damage comes from.

The typical range is roughly 0.8–1.33 (often cited as “around 1.33”). On its own the ratio is a supporting clue, not a standalone diagnosis.

How to read the ratio

A ratio below 0.8 (ALT predominance) is typical of hepatocellular injury — viral hepatitis and non-alcoholic fatty liver disease (NAFLD). A ratio above 1.33 with AST predominance is seen with a cardiac/muscle source and with progression of fibrosis. A ratio of 2 and above is classically linked to alcoholic liver disease and cirrhosis.

Importantly, the ratio is meaningful when the enzymes themselves are elevated. With normal AST and ALT it carries almost no diagnostic value.

Frequently asked questions

Divide AST by ALT (both in U/L). The calculator does it instantly — enter the values from a blood chemistry panel.
The typical range is about 0.8–1.33. Below 0.8 points to hepatocellular injury, above 1.33 to a cardiac/muscle source or progression, 2 and above to alcoholic injury or cirrhosis.
An AST/ALT ratio of 2 and above is classically linked to alcoholic liver disease and cirrhosis. It’s a guide that needs a doctor’s assessment alongside other tests.
The ratio is only one detail. Elevated enzymes themselves warrant attention and a doctor’s work-up of the cause, regardless of the ratio.

AST and ALT are part of the liver picture

Upload your blood chemistry — the AI reads the liver enzymes together, weighs the De Ritis ratio in context and tells you what to do.

Analyze blood chemistry

This calculator is for information only and is not a diagnosis. The cause of changed liver enzymes is assessed by a doctor.