Blood Volume Calculator
Enter your height, weight and sex to estimate your total blood volume using the standard Nadler formula.
How total blood volume is estimated
Total blood volume cannot be measured directly without specialized lab tests, so it is commonly estimated from height, weight and sex using the Nadler equation, a formula derived from studies of body composition that is still widely referenced in medicine today.
The formula
For men: Blood Volume (L) = 0.3669 × height(m)³ + 0.03219 × weight(kg) + 0.6041. For women: Blood Volume (L) = 0.3561 × height(m)³ + 0.03308 × weight(kg) + 0.1833. This calculator also splits the estimate into approximate plasma and red blood cell volume using typical hematocrit values (about 45% for men and 40% for women).
- Average adult blood volume is roughly 4.5-5.5 liters
- Hematocrit is the percentage of blood volume made up of red blood cells
This is a population-average estimate for general educational and reference purposes only, not a measured value. Actual blood volume and hematocrit vary by individual and health status; consult a healthcare professional for clinical assessment.