1. What is Hematocrit (HCT)?

Hematocrit (HCT) is the volume percentage of red blood cells in blood. It is a crucial measurement in assessing blood composition and diagnosing conditions like anemia or polycythemia.

2. How Does the Calculator Work?

The calculator uses the hematocrit formula:

Where:

• \( RBC\_volume \) — Volume of red blood cells (mL)
• \( total\_blood\_volume \) — Total blood volume (mL)

Explanation: The formula calculates what percentage of the total blood volume is occupied by red blood cells.

3. Importance of HCT Measurement

Details: Hematocrit is important for diagnosing and monitoring blood disorders, assessing hydration status, and evaluating oxygen-carrying capacity of blood.

4. Using the Calculator

Tips: Enter RBC volume and total blood volume in milliliters (mL). Both values must be positive numbers, and RBC volume cannot exceed total blood volume.

5. Frequently Asked Questions (FAQ)

Q1: What are normal HCT values?
A: Normal ranges vary by sex: typically 38.3-48.6% for men and 35.5-44.9% for women.

Q2: How is HCT measured clinically?
A: Typically measured by centrifuging a blood sample and measuring the proportion of RBCs, or calculated from automated complete blood count (CBC) results.

Q3: What causes high HCT levels?
A: Dehydration, polycythemia vera, chronic hypoxia (e.g., from lung disease or high altitude), or certain tumors.

Q4: What causes low HCT levels?
A: Anemia, blood loss, overhydration, bone marrow disorders, or nutritional deficiencies (iron, B12, folate).

Q5: How does HCT relate to hemoglobin?
A: HCT is approximately three times the hemoglobin value (in g/dL) in healthy individuals (e.g., hemoglobin 15 g/dL ≈ HCT 45%).