Blood Volume Calculator
Estimate how much blood your body holds, using Nadler's formula.
Awaiting Data
Enter your details and tap Calculate to see your results appear here.
Your result appears here.
What it measures
Blood volume is the total amount of blood moving through your body. It rises with size, so taller and heavier people carry more. Clinicians use the figure to plan fluids, transfusions, and certain drug doses.
Nadler's formula estimates the volume from sex, height, and weight. An average adult holds roughly 4.5 to 5.5 litres. For a surgical planning figure, pair this with the Allowable Blood Loss Calculator.
How to use this calculator
- Choose metric or US units.
- Pick your sex.
- Enter your height and weight.
- Tap Calculate for your blood volume.
The formula used
Women: BV = 0.3561 × h(m)³ + 0.03308 × kg + 0.1833
- h(m)
- Height in metres.
- kg
- Body weight in kilograms.
Understanding Your Results
Tips to Improve
- Stay hydrated to keep volume steady.
- Donating blood removes about 0.5 L.
- Volume falls with dehydration.
- Use the figure as a reference, not a diagnosis.
Frequently Asked Questions
Roughly 4.5 to 5.5 litres, varying with body size and sex.
Body composition differs, so the equations differ slightly.
It gives a solid estimate for healthy adults, widely used in medicine.
Scientific References
- Nadler, S. B., et al. (1962). Prediction of blood volume in normal human adults. Surgery, 51(2), 224–232.
- Sharma, R., & Sharma, S. (2023). Physiology, Blood Volume. StatPearls.