Hematocrit to Hemoglobin Ratio Calculator
Calculate HCT/HGB ratio for hemoconcentration assessment and blood parameter relationships
Calculate HCT/HGB Ratio
Normal: Men 40-54%, Women 36-48%
Normal: Men 14-18 g/dL, Women 12-16 g/dL
Results
Ratio Interpretation
Enter both hematocrit and hemoglobin values to calculate ratio
Complete both values for assessment
⚠️ Medical Disclaimer: This calculator provides ratio calculations and estimates for educational purposes only. HCT/HGB ratios should be interpreted in clinical context with other laboratory values and patient assessment. The rule of three is approximate and may not apply to all patients or conditions. Always consult healthcare professionals for proper diagnosis and treatment decisions.
Clinical Applications
• Hemoconcentration detection: Elevated ratio suggests plasma volume loss
• Sample quality assessment: High ratios may indicate specimen concentration
• Dehydration screening: Useful marker for fluid status evaluation
• Laboratory validation: Cross-check for analytical errors or hemolysis
• Clinical monitoring: Track changes in blood concentration over time
Example Clinical Scenarios
Normal Patient
Patient: Healthy 35-year-old male
Hematocrit: 45%
Hemoglobin: 15.0 g/dL
HCT/HGB Ratio: 45 ÷ 15.0 = 3.0
Interpretation: Normal ratio (<3.2) - No hemoconcentration
Mild Dehydration
Patient: Post-operative patient with poor fluid intake
Hematocrit: 48%
Hemoglobin: 14.5 g/dL
HCT/HGB Ratio: 48 ÷ 14.5 = 3.3
Interpretation: Suggestive of hemoconcentration (3.2-3.5)
Significant Hemoconcentration
Patient: Severe dehydration from gastroenteritis
Hematocrit: 52%
Hemoglobin: 14.0 g/dL
HCT/HGB Ratio: 52 ÷ 14.0 = 3.7
Interpretation: Hemoconcentration present (>3.5)
Reference Ranges
Hematocrit (HCT)
• Men: 40-54%
• Women: 36-48%
• Children: 32-44%
Hemoglobin (HGB)
• Men: 14-18 g/dL
• Women: 12-16 g/dL
• Children: 10-14 g/dL
HCT/HGB Ratio
• Normal: <3.2
• Suggestive: 3.2-3.5
• Hemoconcentration: >3.5
Key Points
HCT/HGB ratio helps detect hemoconcentration
Rule of 3: HCT ≈ HGB × 3 in healthy individuals
Ratios >3.5 suggest plasma volume reduction
Useful for dehydration assessment
Can indicate specimen collection issues
Understanding Hematocrit and Hemoglobin
What are Hematocrit and Hemoglobin?
Hematocrit (HCT) represents the volume percentage of red blood cells in blood, while hemoglobin (HGB) is the oxygen-carrying protein within red blood cells. Both are essential markers for diagnosing anemia and polycythemia.
The Rule of Three
In healthy individuals, hematocrit is typically about three times the hemoglobin concentration. This relationship allows estimation of one value from the other when only one is available.
HCT/HGB Ratio Significance
HCT/HGB Ratio = Hematocrit (%) ÷ Hemoglobin (g/dL)
- < 3.2: Normal ratio, adequate hydration
- 3.2-3.5: Suggestive of mild hemoconcentration
- > 3.5: Significant hemoconcentration present
Clinical Pearl: Elevated ratios may indicate dehydration, plasma loss, or specimen concentration issues requiring further evaluation.
Clinical Applications
Diagnostic Uses
- • Hemoconcentration detection
- • Dehydration assessment
- • Sample quality evaluation
- • Laboratory error screening
- • Fluid status monitoring
Causes of Elevated Ratios
- • Dehydration or fluid loss
- • Prolonged tourniquet application
- • Specimen concentration
- • Plasma volume reduction
- • Capillary blood collection issues