How big is a brain?

The brain weighs roughly 1.4 kg (3 lb) in the average human. This organ's size varies greatly among individuals, ranging from 1.2 to 1.7 kg (2.6 to 3.7 lb). Compared to the size of the human body, the brain is about 2% of the total weight. The brain makes up a tiny fraction of the total body weight of most other animals, often less than 1%. The elephant brain is the largest of any land animal, weighing between 4 and 5 kg (8.8 and 11 lb), while the whale brain is the largest overall, weighing up to 9 kg (20 lb).