Brain Facts

The Human Brain

Weight - The average human brain weighs 1,300 - 1,400 grams (approximately 3 pounds).

Volume - Intracranial contents by volume (1,700 ml, 100%):
     brain = 1,400 ml (80%) 47 ounces
     blood = 150 ml (10%) 5 ounces
     cerebrospinal fluid = 150 ml (10%) 5 ounces

Average number of neurons in the brain = 100 billion.

Composition of the whole brain:
     77%   Water
     11%   Lipids
      8%    Protein
      2%    Soluble organic substances
      1%    Carbohydrate
      1%    Inorganic salts

Credit: NeuroScience for Kids
http://faculty.washington.edu/chudler/facts.html#brain