SAAG Calculator (Serum-Ascites Albumin Gradient)
The serum-ascites albumin gradient (SAAG) is the serum albumin minus the ascitic-fluid albumin, measured on samples taken the same day. A gradient of 1.1 g/dL or more indicates portal hypertension (such as cirrhosis or heart failure) with about 97% accuracy, while under 1.1 g/dL points to a non-portal cause.
Quick answer
The serum-ascites albumin gradient (SAAG) is the serum albumin minus the ascitic-fluid albumin, measured on samples taken the same day. A gradient of 1.1 g/dL or more indicates portal hypertension (such as cirrhosis or heart failure) with about 97% accuracy, while a gradient under 1.1 g/dL points to a non-portal cause such as malignancy, infection or pancreatitis.
Albumin values (same-day samples)
Take the serum and ascitic-fluid albumin on the same day for an accurate gradient.
How to use the SAAG calculator
- 1Enter the albumin values. Enter the serum albumin and the ascitic-fluid albumin (both g/dL), ideally from samples taken on the same day.
- 2Read the gradient. The tool subtracts the ascitic albumin from the serum albumin to give the SAAG.
- 3Interpret the cause. A SAAG of 1.1 g/dL or more indicates portal hypertension; under 1.1 g/dL indicates a non-portal cause. A clinician interprets the result with the full picture.
Medical disclaimer: This is general health information, not medical advice. It does not diagnose or treat any condition, and the results are estimates based on public reference formulas. Always consult a qualified doctor about your individual health. If you think you may have a medical emergency, contact your local emergency services immediately.
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Book a consultationFrequently asked questions
What does a high SAAG mean?β
A SAAG of 1.1 g/dL or more indicates portal hypertension β most commonly cirrhosis, but also heart failure, Budd-Chiari syndrome or massive hepatic metastases. It correctly classifies portal-hypertensive ascites about 97% of the time.
What causes a low SAAG?β
A SAAG under 1.1 g/dL suggests a non-portal cause, such as peritoneal malignancy, tuberculous peritonitis, pancreatic ascites or nephrotic syndrome. The gradient narrows the differential but does not give a single diagnosis.
Why is SAAG preferred over the old exudate-transudate concept?β
The original study showed the SAAG classifies ascites more accurately than the total-protein-based exudate-transudate distinction, because it reflects the oncotic pressure gradient that drives portal-hypertensive ascites.
Is my data stored?β
No. The calculator runs entirely in your browser; nothing you enter is sent to a server.
Sources & validation
This calculator reproduces the published SAAG score, validated for classifying ascites as portal-hypertensive or non-portal.
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