π©Έ A/G Ratio Calculator
What your albumin-globulin ratio reveals.
Albumin-to-globulin ratio
For informational purposes only, not medical advice. Consult a healthcare professional.
Your blood carries two main protein families: albumin, made by the liver, and globulins, which include antibodies and transport proteins. The A/G ratio divides one by the other, and the balance between them quietly reflects liver function, kidney health, nutrition, and immune activity.
A normal ratio runs 1.1 to 2.5. When it drops below 1.0, globulins have overtaken albumin, which points toward chronic liver disease, kidney protein loss, or chronic inflammation. This calculator computes the ratio from your albumin and total protein and explains what the number suggests.
How to use this calculator
Find albumin and total protein on your metabolic panel. Both are reported in g/dL by US labs.
Enter albumin in g/dL (typical normal 3.5 to 5.5).
Enter total protein in g/dL (typical normal 6.0 to 8.3).
Read your A/G ratio, the calculated globulin level, and the interpretation.
The formula
Globulin is not measured directly on a basic panel; it is derived by subtracting albumin from total protein. The ratio then compares the two.
Because globulin is calculated, any error in either measurement shifts the ratio. Dehydration concentrates both proteins and can nudge the ratio up; overhydration dilutes them. Borderline results deserve a repeat before anyone draws conclusions.
Worked example
Albumin 4.0 g/dL, total protein 7.0 g/dL. Globulin is 7.0 minus 4.0, or 3.0 g/dL. The A/G ratio is 4.0 divided by 3.0, which is 1.33, comfortably normal.
Now albumin 2.8 with total protein 7.5. Globulin is 4.7, and the ratio is 2.8 divided by 4.7, or 0.60. That is a low ratio driven by low albumin with high globulins, the classic pattern of chronic liver disease or chronic inflammation, and it needs medical follow-up, not internet reassurance.
What low and high ratios suggest
Low ratio (under 1.0): either albumin is down, globulins are up, or both. Low albumin suggests liver disease, malnutrition, or kidney or gut protein loss. High globulins suggest chronic infection, autoimmune disease, or multiple myeloma, which produces a monoclonal globulin spike.
High ratio (over 2.5): less common. Usually low globulins, which can signal immune deficiency, or simply dehydration concentrating albumin. Protein electrophoresis is the follow-up test that sorts globulin patterns properly. For nutrition context that affects albumin, see our protein intake calculator and BMI calculator.
When to recheck vs when to worry
A single borderline result in a healthy person getting routine labs is usually rechecked in a few months, not worked up urgently. Persistent ratios under 1.0, a falling trend across several panels, or a low ratio plus symptoms (fatigue, swelling, frequent infections, bone pain) move faster.
Remember what the ratio cannot do: it cannot distinguish which globulin is high, it cannot diagnose liver disease alone, and it bounces with hydration. It is a screening flag, and the confirmatory tests (liver panel trends, urine protein, serum protein electrophoresis) are what turn the flag into an answer.
Protein electrophoresis: the next test
When the A/G ratio is abnormal, the follow-up is serum protein electrophoresis (SPEP), which separates globulins into five bands: albumin, alpha-1, alpha-2, beta, and gamma. Each band tells a different story. A sharp spike in the gamma region suggests a monoclonal protein, the hallmark of multiple myeloma; a broad gamma hump suggests chronic inflammation or liver disease.
SPEP is also how doctors monitor myeloma treatment: the spike (called the M-spike) shrinks as therapy works. If immunofixation then identifies the exact antibody type, the workup is complete. None of this replaces the simple A/G ratio as a screening flag, but it shows the path from flag to answer.
Trends beat single values
One A/G ratio is a snapshot; three over two years are a story. A ratio drifting from 1.6 to 1.3 to 1.0 while albumin falls and globulins rise paints developing chronic disease far more convincingly than any single number. Labs keep history for exactly this reason, and most patient portals graph it.
When reviewing trends, check that the lab and units stayed constant, and note hydration context: a ratio drawn during a dehydrated ER visit is not comparable to a fasting morning draw. Consistent conditions make trends honest, and honest trends catch disease early.
Dehydration and posture: pre-analytical traps
Two boring factors distort the A/G ratio more than most diseases do. Dehydration concentrates plasma proteins, raising albumin and the ratio; a patient drawn during a stomach bug can look better on paper than they are. Prolonged standing also matters: upright posture pools fluid in the legs, concentrating upper-body blood by up to 10 percent, which is why morning draws after lying down are the standard.
The fix is procedural, not mathematical: draw labs under consistent conditions, note the context on abnormal results, and repeat before acting. A ratio that normalizes when the patient is hydrated and rested was never a disease signal, just a physiology lesson.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
What is a normal A/G ratio?
1.1 to 2.5. Below 1.0 is considered low and above 2.5 high, though exact reference ranges vary slightly between labs.
What causes a low A/G ratio?
Low albumin (liver disease, malnutrition, kidney or intestinal protein loss) or high globulins (chronic infection, autoimmune disease, multiple myeloma). Often both contribute.
What causes a high A/G ratio?
Usually low globulins, which can suggest immune deficiency, or dehydration concentrating the blood proteins. It is less common than a low ratio.
How is globulin calculated?
Total protein minus albumin, both from the metabolic panel. It is a derived value, not a direct measurement, so errors in either input shift it.
Can dehydration affect the A/G ratio?
Yes. Dehydration concentrates all blood proteins and can raise the ratio; overhydration dilutes them. Borderline results should be rechecked when normally hydrated.
What test follows an abnormal A/G ratio?
Serum protein electrophoresis, which separates globulins into their subtypes and identifies monoclonal spikes suggestive of myeloma versus broad inflammatory patterns.
Is a low A/G ratio serious?
It depends on the cause and the trend. A single mildly low value in a well person is often rechecked. A persistently low or falling ratio, especially with symptoms, needs medical evaluation.
Does diet affect albumin levels?
Yes, over time. Prolonged inadequate protein intake lowers albumin, though in the US low albumin more often reflects illness or inflammation than diet. Our protein intake calculator shows daily targets.