<P> The largest brains are those of sperm whales , weighing about 8 kg ( 18 lb ) , and killer whales , weighing about 12 -- 15 lb ( 5.4 -- 6.8 kg ) . An elephant 's brain weighs just over 5 kg ( 11 lb ) and a bottlenose dolphin 's 1.5 to 1.7 kg ( 3.3 to 3.7 lb ) . </P>
<P> The largest brains are those of sperm whales , weighing about 8 kg ( 18 lb ) , and killer whales , weighing about 12 -- 15 lb ( 5.4 -- 6.8 kg ) . An elephant 's brain weighs just over 5 kg ( 11 lb ) and a bottlenose dolphin 's 1.5 to 1.7 kg ( 3.3 to 3.7 lb ) . </P>
who has the biggest brain in the world
who has the biggest brain in the world
sperm whales
sperm whales