Hct/Hgb Ratio
Hematocrit and hemoglobin are key CBC values. Normal ratio ~3:1. Deviations indicate hemoconcentration, hemodilution, or abnormal red cells.
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~3:1 normal ratio High ratio: hemoconcentration Low ratio: hemodilution or anemia
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Why: Hct and Hgb assess anemia, polycythemia, and hydration. Ratio helps detect hemoconcentration or hemodilution.
How: Hgb ≈ Hct ÷ 3. Enter one value to estimate the other. Ratio outside ~2.8-3.2 suggests further evaluation.
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Clinical Scenarios
✅ Normal Adult Male
Healthy male with normal values
✅ Normal Adult Female
Healthy female with normal values
🔶 Mild Anemia
Female with iron deficiency
🟠 Moderate Anemia
Chronic disease anemia
🔴 Severe Anemia
Significant blood loss
📈 Polycythemia
Elevated Hct and Hgb
💧 Hemoconcentration
Dehydration effect
🤰 Pregnancy Anemia
Third trimester physiologic anemia
🏔️ High Altitude
Altitude adaptation
Lab Values (enter at least one)
Patient Information
For informational purposes only — not medical advice. Consult a healthcare professional before acting on results.
🏥 Health Facts
Hct% ≈ Hgb × 3
— Clinical rule
Understanding Hematocrit and Hemoglobin
Hematocrit (Hct) is the percentage of blood volume occupied by red blood cells, while hemoglobin (Hgb) is the oxygen-carrying protein within red cells measured in g/dL. The ratio between them (~3:1) provides valuable clinical information about hydration status and red cell characteristics.
🩸 Hematocrit
Percentage of blood that is red cells
- • Male: 38.3 - 48.6%
- • Female: 35.5 - 44.9%
- • Pregnancy: lower normal
🔴 Hemoglobin
Oxygen-carrying protein (g/dL)
- • Male: 13.2 - 16.6 g/dL
- • Female: 11.6 - 15.0 g/dL
- • Anemia: <12/13 g/dL
📊 Ratio (Hct/Hgb)
Normal ~3:1
- • >3.4: Hemoconcentration
- • <2.8: Hemodilution
- • 2.9-3.2: Normal range
Anemia Classification
| Type | MCV | Common Causes | Key Tests |
|---|---|---|---|
| Microcytic Anemia | <80 fL | Iron deficiency, Thalassemia, Chronic disease | Iron studies, Ferritin |
| Normocytic Anemia | 80-100 fL | Acute blood loss, Chronic disease, Renal failure | Reticulocyte count, LDH |
| Macrocytic Anemia | >100 fL | B12 deficiency, Folate deficiency, MDS | B12, Folate levels, TSH |
Clinical Significance of Ratio Changes
📈 Elevated Ratio (>3.4)
Hemoconcentration - plasma volume decreased relative to RBC mass
- • Dehydration
- • Burns
- • Diarrhea/vomiting
- • Diuretic use
- • Diabetes insipidus
📉 Decreased Ratio (<2.8)
Hemodilution - plasma volume increased relative to RBC mass
- • IV fluid overload
- • Pregnancy
- • Hemolysis (MCHC elevated)
- • Hypersplenism
- • Lab error (hemolyzed sample)
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