What is the size of a adult penguin?

The largest of the penguin species is the emperor penguin, which has a height of 4 feet and a weight of 80-90 lbs (36.28739 to 40.82331 kilograms).

The smallest penguin species is the "Little Penguin" (Eudyptula minor) being about 16 inches (43 cm) tall, which weighs about 2.2 pounds (one kg).