The adult human brain weighs on average about 1.3–1.4 kg (2.9–3.1 lb), or about 2% of total body weight,[1][2] with a volume of around 1130 cubic centimetres (cm3) in women and 1260 cm3 in men, although there is substantial individual variation.[3] Neurological differences between the sexes have not been shown to correlate in any simple way with IQ or other measures of cognitive performance.[4]
The human brain is composed of neurons, glial cells, and blood vessels. The number of neurons, according to array tomography, has been shown to be on average about 86 billion in the adult male human brain with a roughly equal number of non-neuronal cells. Out of these, 16 billion (or 19% of all brain neurons) are located in the cerebral cortex (including subcortical white matter), 69 billion (or 80% of all brain neurons) are in the cerebellum, and fewer than 1% of all brain neurons are located in the rest of the brain.[5]