How do you calculate the AST to ALT ratio?

Divide AST by ALT using the same units (usually U/L): AST/ALT ratio = AST ÷ ALT. Example: AST 70 U/L and ALT 35 U/L → 70 ÷ 35 = 2.0. The inverse (ALT÷AST) is sometimes called “ALT/AST ratio”; this calculator reports the conventional AST/ALT form used in hepatology literature. Enter your lab values above for an instant ratio and teaching interpretation.

What is a normal AST/ALT ratio?

When both enzymes are within the lab reference range, the ratio is often near 1.0–1.5 and has limited standalone meaning—a healthy person with AST 25 and ALT 22 has ratio ~1.14. The ratio becomes most useful when at least one transaminase is elevated. Teaching bands: <1 (ALT-predominant), 1–2 (balanced), ≥2 (AST-predominant). Always compare to your laboratory’s AST and ALT reference intervals.

What does an AST/ALT ratio less than 1 mean?

ALT exceeds AST. Common causes include non-alcoholic fatty liver disease (typical ratio 0.3–0.8), acute or chronic viral hepatitis, autoimmune hepatitis, and drug-induced liver injury (statins, antibiotics, acetaminophen overdose with very high ALT). Example: AST 60, ALT 120 → ratio 0.5 fits NAFLD or hepatitis pattern. Confirm with history, metabolic risk factors, serologies, and imaging—not ratio alone.

What does an AST/ALT ratio of 2 or higher mean?

AST is at least double ALT—a pattern classically associated with alcoholic liver disease (sensitivity ~80% for alcohol-related injury when enzymes are elevated). Ratio ≥2 also appears in advanced cirrhosis, Wilson disease (rare), and non-hepatic AST release (rhabdomyolysis, hemolysis, myocardial infarction). In alcoholic hepatitis, AST is often modestly elevated (typically 3 is highly suggestive of alcoholic hepatitis in the appropriate clinical setting.

What are normal AST and ALT levels?

Typical adult reference ranges (vary by lab): AST about 10–40 U/L, ALT about 7–56 U/L. ALT is more liver-specific; AST is also in heart, skeletal muscle, kidney, and erythrocytes. Sex, BMI, and assay method shift upper limits. Mild elevations (1–2× ULN) warrant repeat testing and risk-factor review; marked elevations (>10× ULN) suggest acute hepatocellular injury and urgent evaluation.

Is AST the same as SGOT and ALT the same as SGPT?

Yes. SGOT (serum glutamic-oxaloacetic transaminase) is the older name for AST; SGPT (serum glutamic-pyruvic transaminase) is the older name for ALT. “SGOT/SGPT ratio” means the same calculation as AST/ALT ratio on this page.

Can medications raise AST and ALT and change the ratio?

Many drugs cause hepatocellular injury—often with ALT predominance (ratio <1): acetaminophen, amoxicillin-clavulanate, statins, NSAIDs, antiepileptics, methotrexate, and some herbal products (e.g., green tea extract, kava). Statin-related elevations are usually mild and reversible. Always correlate with start/stop dates, dose, and other hepatotoxins. Most cases improve after stopping the offending agent under medical supervision.

What non-liver conditions can elevate AST more than ALT?

Skeletal muscle injury (strenuous exercise, rhabdomyolysis), hemolysis, and acute myocardial infarction can raise AST from non-hepatic sources while ALT stays lower—pushing the ratio upward without alcohol. Check CK, troponin, and clinical context. Repeat labs after recovery from acute muscle injury before attributing a high ratio to liver disease.

How is the AST/ALT ratio used with other liver tests?

The ratio is one clue in a full workup: bilirubin, alkaline phosphatase, GGT, platelets, INR, albumin, viral hepatitis serologies, alcohol history, ultrasound, and fibrosis scores (FIB-4, APRI, elastography). For cirrhosis severity and prognosis, use dedicated tools such as our Child-Pugh score calculator. The ratio does not stage fibrosis by itself.

When should I worry about my liver enzyme results?

Seek prompt medical care for jaundice, ascites, encephalopathy, INR elevation, or severe abdominal pain. Concerning lab patterns include: either enzyme >10× ULN, persistent elevation >6 months, ratio ≥2 with elevated enzymes and heavy alcohol use, or falling albumin/platelets suggesting cirrhosis. This calculator does not diagnose disease—use it for education and bring results to your clinician.

How often should AST and ALT be rechecked?

Depends on context: screening every 1–2 years if baseline normal; repeat in 2–4 weeks for new mild elevations; every 3–6 months for known chronic liver disease; statin monitoring per protocol (often baseline, ~3 months, then annually); monthly or more often during active hepatitis treatment. Your provider sets timing based on trend, symptoms, and risk.

Does the AST/ALT ratio predict how severe liver disease is?

It hints at etiology more than stage. High ratio with alcohol history suggests alcohol-related injury; low ratio favors metabolic or viral causes. Prognosis and fibrosis require Child-Pugh, MELD, imaging elastography, or biopsy—not the ratio alone. In cirrhosis, both enzymes may normalize low while ratio drifts upward as disease advances.

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Q: What does an AST/ALT ratio less than 1 mean?

ALT exceeds AST. Common causes include non-alcoholic fatty liver disease (typical ratio 0.3–0.8), acute or chronic viral hepatitis, autoimmune hepatitis, and drug-induced liver injury (statins, antibiotics, acetaminophen overdose with very high ALT). Example: AST 60, ALT 120 → ratio 0.5 fits NAFLD or hepatitis pattern. Confirm with history, metabolic risk factors, serologies, and imaging—not ratio alone.

Q: What does an AST/ALT ratio of 2 or higher mean?

AST is at least double ALT—a pattern classically associated with alcoholic liver disease (sensitivity ~80% for alcohol-related injury when enzymes are elevated). Ratio ≥2 also appears in advanced cirrhosis, Wilson disease (rare), and non-hepatic AST release (rhabdomyolysis, hemolysis, myocardial infarction). In alcoholic hepatitis, AST is often modestly elevated (typically 3 is highly suggestive of alcoholic hepatitis in the appropriate clinical setting.

Q: What are normal AST and ALT levels?

Typical adult reference ranges (vary by lab): AST about 10–40 U/L, ALT about 7–56 U/L. ALT is more liver-specific; AST is also in heart, skeletal muscle, kidney, and erythrocytes. Sex, BMI, and assay method shift upper limits. Mild elevations (1–2× ULN) warrant repeat testing and risk-factor review; marked elevations (>10× ULN) suggest acute hepatocellular injury and urgent evaluation.

Q: What non-liver conditions can elevate AST more than ALT?

Skeletal muscle injury (strenuous exercise, rhabdomyolysis), hemolysis, and acute myocardial infarction can raise AST from non-hepatic sources while ALT stays lower—pushing the ratio upward without alcohol. Check CK, troponin, and clinical context. Repeat labs after recovery from acute muscle injury before attributing a high ratio to liver disease.

Q: How is the AST/ALT ratio used with other liver tests?

The ratio is one clue in a full workup: bilirubin, alkaline phosphatase, GGT, platelets, INR, albumin, viral hepatitis serologies, alcohol history, ultrasound, and fibrosis scores (FIB-4, APRI, elastography). For cirrhosis severity and prognosis, use dedicated tools such as our Child-Pugh score calculator. The ratio does not stage fibrosis by itself.

Q: When should I worry about my liver enzyme results?

Seek prompt medical care for jaundice, ascites, encephalopathy, INR elevation, or severe abdominal pain. Concerning lab patterns include: either enzyme >10× ULN, persistent elevation >6 months, ratio ≥2 with elevated enzymes and heavy alcohol use, or falling albumin/platelets suggesting cirrhosis. This calculator does not diagnose disease—use it for education and bring results to your clinician.

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Hepatology & lab interpretation

AST/ALT Ratio Calculator

Calculate the De Ritis ratio (AST ÷ ALT) from your liver panel. The AST/ALT ratio helps distinguish metabolic and viral hepatitis (ALT-predominant) from alcohol-related injury (AST-predominant) when transaminases are elevated—not when both are normal. Pair with our Child-Pugh calculator for cirrhosis staging.

Last updated: June 4, 2026

Instant ratio with NAFLD / alcohol / balanced bands

Flags when only AST or only ALT is elevated

SGOT/SGPT (AST/ALT) reference ranges included

AST/ALT Ratio Calculator

Calculate AST to ALT ratio for liver function assessment

AST (Aspartate Aminotransferase)

Normal range: 10-40 U/L (may vary by lab)

ALT (Alanine Aminotransferase)

Normal range: 7-56 U/L (may vary by lab)

Ratio Analysis

AST/ALT Ratio

1.25

Balanced ratio (AST/ALT 1–2)

Severity Assessment:

Context-dependent — check absolute levels

Clinical Interpretation:

May reflect chronic hepatitis, early alcohol-related injury, or normal variant

AST Normal:

10–40 U/L

ALT Normal:

7–56 U/L

Clinical Considerations:

•Both within typical reference range — ratio alone has limited diagnostic weight
•Assess alcohol use with validated screening tools
•Trend enzymes over 2–4 weeks if newly elevated
•Consider fibrosis assessment (FIB-4, elastography) if chronic elevation

Important Medical Notice:

• This calculator is for educational purposes only
• Not a substitute for professional medical diagnosis
• Always consult healthcare provider for interpretation
• Lab reference ranges may vary by testing facility
• Consider full clinical context and additional tests

Worked examples

Normal enzymes

AST 35, ALT 28

1.25

Ratio near 1; limited significance when normal

NAFLD-style

AST 60, ALT 120

0.5

ALT predominant (<1)

Alcohol-related pattern

AST 180, ALT 60

AST ≥2× ALT

Acute viral hepatitis

AST 800, ALT 950

0.84

Very high ALT; ratio often <1

AST/ALT ratio formula

Also called the De Ritis ratio or SGOT/SGPT ratio:

AST/ALT ratio = AST (U/L) ÷ ALT (U/L)

Example: 35 ÷ 28 = 1.25. ALT/AST is the reciprocal (28 ÷ 35 ≈ 0.80)—this tool reports AST÷ALT.

Interpretation chart

Ratio	Pattern	Often suggests	Notes
< 1	ALT > AST	NAFLD/NASH (often 0.3–0.8), acute viral hepatitis, many drug-induced injuries	Most common pattern in metabolic liver disease
1 – 2	Balanced	Chronic hepatitis B/C, indeterminate early alcohol injury, some cirrhosis	Interpret with alcohol history and imaging
≥ 2	AST > ALT	Alcoholic hepatitis (~80% sensitivity), alcoholic cirrhosis, advanced cirrhosis	Ratio > 3 strongly favors alcohol; AST rarely >500 in pure alcoholic hepatitis
> 3	Markedly AST-predominant	Alcoholic hepatitis (classic), Wilson disease (uncommon), severe cirrhosis	Exclude recent strenuous exercise and rhabdomyolysis

Bands apply when at least one transaminase is above the reference interval.

AST and ALT reference ranges

AST (SGOT)

Aspartate aminotransferase

~10–40 U/L

Liver, heart, skeletal muscle, kidney, erythrocytes. Non-hepatic AST can raise the ratio without primary liver disease.

ALT (SGPT)

Alanine aminotransferase

~7–56 U/L

More specific for hepatocellular injury. NAFLD and viral hepatitis typically elevate ALT more than AST.

Common conditions by ratio pattern

Condition	Typical ratio	Enzyme pattern
NAFLD / NASH	0.3 – 0.8	Mild–moderate ALT rise; AST often lower
Acute viral hepatitis	0.5 – 1.0	Often both >500 U/L; ALT ≥ AST early
Alcoholic hepatitis	2 – 6+	AST often 2–4× ULN; AST > ALT
Cirrhosis (any cause)	1 – 4	May be only mildly elevated late
Rhabdomyolysis / exercise	Variable, often >1	AST from muscle; ALT less affected

References

Cohen JA, Kaplan MM (1979)AST/ALT ratio as an indicator of alcoholic liver disease — foundational teaching reference.
AASLD — Liver disease practice guidance
ACG — Evaluation of abnormal liver chemistries

Not medical advice. Lab ranges differ by facility; diagnosis requires history, examination, and additional testing. Seek urgent care for jaundice, confusion, or severe abdominal pain.

Frequently Asked Questions

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Hepatology & lab interpretation

AST/ALT Ratio Calculator

Last updated: June 4, 2026

Instant ratio with NAFLD / alcohol / balanced bands

Flags when only AST or only ALT is elevated

SGOT/SGPT (AST/ALT) reference ranges included

AST/ALT Ratio Calculator

Calculate AST to ALT ratio for liver function assessment

AST (Aspartate Aminotransferase)

Normal range: 10-40 U/L (may vary by lab)

ALT (Alanine Aminotransferase)

Normal range: 7-56 U/L (may vary by lab)

Ratio Analysis

AST/ALT Ratio

1.25

Balanced ratio (AST/ALT 1–2)

Severity Assessment:

Context-dependent — check absolute levels

Clinical Interpretation:

May reflect chronic hepatitis, early alcohol-related injury, or normal variant

AST Normal:

10–40 U/L

ALT Normal:

7–56 U/L

Clinical Considerations:

•Both within typical reference range — ratio alone has limited diagnostic weight
•Assess alcohol use with validated screening tools
•Trend enzymes over 2–4 weeks if newly elevated
•Consider fibrosis assessment (FIB-4, elastography) if chronic elevation

Important Medical Notice:

• This calculator is for educational purposes only
• Not a substitute for professional medical diagnosis
• Always consult healthcare provider for interpretation
• Lab reference ranges may vary by testing facility
• Consider full clinical context and additional tests

Worked examples

Normal enzymes

AST 35, ALT 28

1.25

Ratio near 1; limited significance when normal

NAFLD-style

AST 60, ALT 120

0.5

ALT predominant (<1)

Alcohol-related pattern

AST 180, ALT 60

AST ≥2× ALT

Acute viral hepatitis

AST 800, ALT 950

0.84

Very high ALT; ratio often <1

AST/ALT ratio formula

Also called the De Ritis ratio or SGOT/SGPT ratio:

AST/ALT ratio = AST (U/L) ÷ ALT (U/L)

Example: 35 ÷ 28 = 1.25. ALT/AST is the reciprocal (28 ÷ 35 ≈ 0.80)—this tool reports AST÷ALT.

Interpretation chart

Ratio	Pattern	Often suggests	Notes
< 1	ALT > AST	NAFLD/NASH (often 0.3–0.8), acute viral hepatitis, many drug-induced injuries	Most common pattern in metabolic liver disease
1 – 2	Balanced	Chronic hepatitis B/C, indeterminate early alcohol injury, some cirrhosis	Interpret with alcohol history and imaging
≥ 2	AST > ALT	Alcoholic hepatitis (~80% sensitivity), alcoholic cirrhosis, advanced cirrhosis	Ratio > 3 strongly favors alcohol; AST rarely >500 in pure alcoholic hepatitis
> 3	Markedly AST-predominant	Alcoholic hepatitis (classic), Wilson disease (uncommon), severe cirrhosis	Exclude recent strenuous exercise and rhabdomyolysis

Bands apply when at least one transaminase is above the reference interval.

AST and ALT reference ranges

AST (SGOT)

Aspartate aminotransferase

~10–40 U/L

Liver, heart, skeletal muscle, kidney, erythrocytes. Non-hepatic AST can raise the ratio without primary liver disease.

ALT (SGPT)

Alanine aminotransferase

~7–56 U/L

More specific for hepatocellular injury. NAFLD and viral hepatitis typically elevate ALT more than AST.

Common conditions by ratio pattern

Condition	Typical ratio	Enzyme pattern
NAFLD / NASH	0.3 – 0.8	Mild–moderate ALT rise; AST often lower
Acute viral hepatitis	0.5 – 1.0	Often both >500 U/L; ALT ≥ AST early
Alcoholic hepatitis	2 – 6+	AST often 2–4× ULN; AST > ALT
Cirrhosis (any cause)	1 – 4	May be only mildly elevated late
Rhabdomyolysis / exercise	Variable, often >1	AST from muscle; ALT less affected

References

Cohen JA, Kaplan MM (1979)AST/ALT ratio as an indicator of alcoholic liver disease — foundational teaching reference.
AASLD — Liver disease practice guidance
ACG — Evaluation of abnormal liver chemistries

Not medical advice. Lab ranges differ by facility; diagnosis requires history, examination, and additional testing. Seek urgent care for jaundice, confusion, or severe abdominal pain.