Your brain is slightly larger than the size of your two fists. An average adult brain weighs around 1.3 to 1.5 kg (about 3 lb) and has these dimensions: Average brain width = 140 mm Average brain length = 167 mm Average brain height = 93 mm
The average human brain weighs three pounds (1.36 kilograms). The average female brain capacity is 79.3 cubic inches, slightly smaller than the male brain of 88.5 cubic inches. The largest human brains may be twice those of average size, but size has no relevance to brain performance.