Calculate the serum-ascites albumin gradient to separate portal-hypertensive from other causes of ascites.
Result
How to use this tool
Enter serum albumin in g/dL.
Enter ascitic fluid albumin in g/dL from the same sampling time.
Read the gradient.
Compare it with the 1.1 g/dL threshold.
Formula & worked example
Serum albumin 3.5 minus ascitic albumin 1.0 gives a SAAG of 2.5 g/dL, above 1.1, suggesting portal hypertension.
Limitations — read this before you rely on it
A classification aid only; mixed causes and timing errors blur the threshold, and it never replaces clinical diagnosis. This tool is for education only and is not medical advice. Talk to a clinician about any result that worries you, and never change treatment because of a calculator result.
Frequently asked questions
The serum-ascites albumin gradient, the difference between blood and ascitic fluid albumin levels.
Above 1.1 g/dL, raised portal pressure drives ascites; below it, other causes like infection or malignancy dominate.
Yes. Serum and ascitic samples should be taken at the same time for a valid gradient.
No. It points to portal hypertension, which has several causes beyond cirrhosis.
Borderline values need clinical review, repeat sampling and other tests; do not decide on the number alone.