# SAAG Calculator (Serum-Ascites Albumin Gradient)

URL: https://speedycalculator.com/calculators/health/saag/
Last updated: 2026-10-30

> The SAAG calculator subtracts the ascitic fluid albumin from the serum albumin to tell whether ascites is caused by portal hypertension (gradient ≥ 1.1 g/dL), as in cirrhosis or heart failure, or by other causes such as cancer or infection.

## Inputs

- Serum albumin (g/dL, g/L)
- Ascitic fluid albumin (g/dL, g/L)
- Ascitic total protein (optional) (g/dL, g/L)

## Results

- SAAG
- Likely group of causes

## Formula

```
SAAG = serum albumin − ascites albumin (g/dL)
≥ 1.1 g/dL: portal hypertension (about 97% accurate)
< 1.1 g/dL: non-portal causes
```

## Explanation

The SAAG has replaced the old transudate/exudate classification of ascites because it predicts portal hypertension much more accurately. Both samples should be taken on the same day.

### How to use the SAAG Calculator

- **Serum albumin**
- **Ascitic fluid albumin**
- **Ascitic total protein (optional)**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter serum and ascitic albumin measured the same day. The calculator subtracts them; ascitic total protein helps distinguish cirrhosis (< 2.5 g/dL) from heart failure (≥ 2.5 g/dL) when SAAG is high.

### Tips

- Use results from the same fasting state the formula expects (most lipid formulas assume fasting).
- Check the units on your lab report before entering values.
- Discuss treatment targets with your clinician – they depend on your overall risk.
- Repeat abnormal results; a single value can be misleading.

### Common mistakes to avoid

- Using Friedewald LDL when triglycerides are above 400 mg/dL.
- Mixing mg/dL and mmol/L values in one calculation.
- Ignoring other risk factors such as smoking and blood pressure.

### Inputs explained

FieldWhat to enterSerum albuminUnits: g/dL, g/LAscitic fluid albuminUnits: g/dL, g/LAscitic total protein (optional)Units: g/dL, g/L

### Example values

How the main result changes when **Serum albumin** changes and everything else stays at the example values above:

Serum albumin (g/dL)SAAG (g/dL)1.60.62.41.43.22.2434.83.86.45.4
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — Serum albumin: 3.2 g/dL; Ascitic fluid albumin: 1 g/dL; Ascitic total protein (optional): 0 g/dL.

Results — **SAAG = 2.2 g/dL**; Likely group of causes = Portal hypertension (cirrhosis, heart failure, Budd–Chiari).

## Key terms

- **Ascites**: Fluid in the abdominal cavity.
- **Portal hypertension**: High pressure in the portal vein, usually from cirrhosis.

## FAQ

**What does a SAAG of 1.1 or more mean?**
Portal hypertension is the likely cause of the ascites.

**Do the samples need to be taken together?**
Yes – on the same day, ideally within hours.

**Can SAAG be wrong?**
Very low serum albumin or hyperglobulinaemia can affect it.


## Sources

- [Runyon BA et al. The serum-ascites albumin gradient is superior to the exudate-transudate concept. Ann Intern Med, 1992](https://pubmed.ncbi.nlm.nih.gov/1616406/)