Blood volume

Blood volume is the volume of blood (both red blood cells and plasma) in the circulatory system of any individual.

Humans

A typical adult has a blood volume of approximately between 4.7 and 5 litres, with females generally having less blood volume than males.[1] 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):

$BV = \frac{PV}{1-HC}$

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.

Blood volume measurement is indicated for the diagnosis and treatment patients suffering from Congestive Heart Failure, Chronic hypertension, Renal Failure and Critical Care.

Other Animals

Animal Blood volume
(ml/kg)[2]
Cat 55 (47-66)
Cow 55 (52-57) [3]
Dog 86 (79-90)
Ferret 75
Gerbil 67
Goat 70
Guinea pig 75 (67-92)
Hamster 78
Horse 76
Human 77
Monkey (rhesus) 54
Mouse 79 (78-80)
Pig 65
Rabbit 56 (44-70)
Rat 64 (50-70)
Sheep 60
Marmoset 60-70[4]

The table at right shows circulating blood volumes, given as volume per kilogram, for healthy adults of a selection of animals.[2] However, it can be 15% less in obese and old animals.[2]