For healthcare professionals

SAAG Calculator

The serum-ascites albumin gradient (SAAG) is the serum albumin minus the albumin in the ascitic fluid. A gradient of 1.1 g/dL or more points to portal hypertension as a cause of the ascites. This tool is written for clinicians and is not a diagnosis.

Last reviewed: 2026-11-02 By the uncovermyrisk.com editorial team Educational only, not medical advice.

Vomiting blood, severe abdominal pain or confusion: call 911 now.General safety advice (not part of the published cut-off). Do not wait for laboratory results.

Albumin values

Use serum and ascitic fluid albumin measured on the same day. Nothing you enter leaves this page.

Unit Serum albumin Ascitic fluid albumin

Result appears here

What you will see

The gradient with the working, and whether it is at or above the 1.1 g/dL cut-off.

Educational only, not medical advice. Not a diagnosis. Decisions belong to the treating team.

Source

The formula as printed in the Austrian portal hypertension consensus by Reiberger T and colleagues, Wiener klinische Wochenschrift 2017; the 1.1 g/dL cut-off from the Japanese cirrhosis guidelines by Yoshiji H and colleagues, Journal of Gastroenterology 2021; and the accuracy figure from the review by Al-Busafi SA and colleagues, International Journal of Hepatology 2012, citing Runyon BA and colleagues, Annals of Internal Medicine 1992. All three are open access (CC BY). The tests check the formula, the cut-off edge (exactly 1.1 g/dL or 11 g/L counts as 1.1 or more) and that a value is never rounded onto the cut-off it is not on.

Validated in

People with ascites who have a diagnostic paracentesis. The accuracy figure comes from the 1992 study by Runyon and colleagues, as cited by Al-Busafi 2012.

Limits

There are exceptions to the cut-off, so the cause of ascites is judged as a whole (Yoshiji 2021). The serum and ascitic albumin should be measured on the same day (Reiberger 2017). Reiberger 2017 writes that uncomplicated portal hypertensive ascites shows a SAAG over 1.1 g/dl, while Yoshiji 2021 and Al-Busafi 2012 use 1.1 or more; the tool uses 1.1 or more.

The formula

SAAG = serum albumin - ascitic fluid albumin, both measured on the same day (Reiberger 2017).

Worked example: serum albumin 3.0 g/dL and ascitic albumin 1.0 g/dL give 3.0 - 1.0 = 2.0 g/dL, which is 1.1 or more.

Reading the result

1.1 g/dL (11 g/L) or more: portal hypertension is involved in forming the ascites, with high accuracy (Yoshiji 2021), about 97% in the study cited by Al-Busafi and colleagues (Al-Busafi 2012).
Under 1.1 g/dL: the gradient does not attribute the ascites to portal hypertension (Yoshiji 2021).

The SAAG is more reliable than the older exudate-transudate concept based on ascitic protein (Yoshiji 2021). Investigation of ascites should also include the ascitic neutrophil count and protein; uncomplicated portal hypertensive ascites is expected to show a neutrophil count under 250 per microliter and a protein under 2.5 g/dl (Reiberger 2017).

Related tools

For severity in cirrhosis, see the Child-Pugh score calculator, which includes ascites as one item, and the MELD score calculator. Other bedside scores are listed under For healthcare professionals.

Sources

Reiberger T, Puspok A, Schoder M, Baumann-Durchschein F, Bucsics T, Datz C, et al. Austrian consensus guidelines on the management and treatment of portal hypertension (Billroth III). Wien Klin Wochenschr. 2017;129(Suppl 3):135-158. doi:10.1007/s00508-017-1262-3. PMID 29063233. Open access (CC BY 4.0). Section on ascites (SAAG calculation, same-day samples, expected neutrophil count, SAAG and protein). pmc.ncbi.nlm.nih.gov/articles/PMC5674135/
Yoshiji H, Nagoshi S, Akahane T, Asaoka Y, Ueno Y, Ogawa K, et al. Evidence-based clinical practice guidelines for Liver Cirrhosis 2020. J Gastroenterol. 2021;56(7):593-619. doi:10.1007/s00535-021-01788-x. PMID 34231046. Open access (CC BY 4.0). Ascites, BQ 4-3 (SAAG 1.1 g/dL cut-off, exceptions, comparison with the exudate-transudate concept). pmc.ncbi.nlm.nih.gov/articles/PMC8280040/
Al-Busafi SA, McNabb-Baltar J, Farag A, Hilzenrat N. Clinical manifestations of portal hypertension. Int J Hepatol. 2012;2012:203794. doi:10.1155/2012/203794. PMID 23024865. Open access (CC BY). Section on ascites (SAAG 1.1 g/dL or more, about 97% accuracy, citing Runyon BA et al. Ann Intern Med 1992;117:215-220). pmc.ncbi.nlm.nih.gov/articles/PMC3457672/

Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-11-02. Spotted an error? See About.