Normal blood volume: 

1. About 4 to 5 litres
2. About 3 to 4 litres
3. About 2 to 3 litres
4. About 6 to 7 litres

Normal blood volume average is 7% of body weight – 5L for 70kg adults. Plasma (55%) carries cells (RBCs, WBCs, platelets). Blood doping artificially increases volume for athletic performance.