12/04/2026
Heart sizes vary greatly among different animals, showing how body size affects organ size. A human heart weighs about 300 grams, making it the smallest among those shown. The giraffe’s heart is much larger at 11 kg, adapted to pump blood up its long neck. The African elephant’s heart is even bigger at 20 kg, supporting its massive body. The blue whale has the largest heart at 180 kg, highlighting the enormous scale of the largest animal on Earth.