What this calculator does
A total protein result lumps together two quite different groups: albumin, made by the liver, and the globulins, which include antibodies. The ratio between them says more than the total does, because the two can move in opposite directions while the total stays put.
Globulin is never measured directly on a standard panel. It is total protein less albumin, so an albumin of 4.0 g/dL against a total of 7.0 leaves 3.00 g/dL of globulin and a ratio of 1.33.
The formula
Subtract albumin from total protein to get globulin, then divide albumin by that figure. Both values come from the same routine panel.
| Term | Meaning |
|---|---|
| Albumin | The most abundant blood protein, made by the liver. |
| Globulin | Everything else in total protein, including antibodies. Calculated rather than measured. |
| A/G ratio | Albumin divided by globulin, typically 1.1 to 2.5. |
The inputs explained
| Field | What to enter |
|---|---|
| Albumin (g/dL) | Serum albumin in g/dL. |
| Total protein (g/dL) | Total protein in g/dL, from the same sample. |
When to use it
Reading a comprehensive metabolic panel
Both values appear routinely and the ratio adds information neither gives alone.
Understanding why a total looks normal
Albumin falling while globulin rises can leave the total unchanged.
Following a trend over time
A drifting ratio is often more informative than either component.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How does albumin move the ratio?
The same total protein at three albumin levels.
| Albumin | Albumin-to-globulin ratio | Globulin |
|---|---|---|
| 3.0 g/dL | 0.75 | 4.00 g/dL |
| 4.0 g/dL | 1.33 | 3.00 g/dL |
| 5.0 g/dL | 2.50 | 2.00 g/dL |
Questions
Why is globulin not measured directly?
Because it is not a single substance but a family of proteins, and measuring them individually needs electrophoresis rather than a routine assay. Subtracting albumin from total protein is the standard shortcut.
What does a low ratio suggest?
Either less albumin or more globulin, which have quite different causes. Liver disease and kidney protein loss lower albumin, while some chronic conditions raise globulin. The ratio flags the pattern without identifying which applies.
What does a high ratio suggest?
Usually low globulin, which is less common than low albumin and can point toward reduced antibody production. It also appears with dehydration, which concentrates albumin.
Can I interpret this myself?
Not meaningfully. The ratio is one pattern among many on a panel and needs to be read with the rest of the results, your history and your symptoms. Discuss any abnormal value with the clinician who ordered the test.
For the liver enzyme pattern on the same panel, see the AST-to-ALT ratio calculator. For calcium adjusted against albumin, see the corrected calcium calculator.