A typical adult has a blood volume of approximately 5 liters, with females generally having less blood volume than males. Blood volume is regulated by the kidneys.
Blood volume (BV) can be calculated given the hematocrit (HC; the fraction of blood that is red blood cells) and plasma volume (PV):
Diagnostic technologies are commercially available to measure human blood volume. A recent radionucleotide study called BVA-100, Blood Volume Analysis is the only FDA approved instrument that provides a measure of Red Blood Cells and Plasma with 98% accuracy.