How Tall Is an Emperor Penguin? Size and Weight Facts

Emperor penguin height: the real numbers

Height sounds easy to measure, but for penguins it causes a lot of confusion. Scientists usually measure birds lying flat, from the tip of the bill to the tip of the tail. For an adult emperor penguin, that body length is about 1.1–1.3 m (3.6–4.3 ft).

A living penguin rarely stands fully stretched. It holds its head slightly forward and rests on short legs that are partly hidden inside its body. So its standing height is noticeably lower than its length. Measurements of wild birds and museum skins have produced standing heights of roughly 0.8–1.1 m (2.7–3.6 ft), with most adults close to 1 m (3.3 ft).

Popular sources often quote 1.2 m (3.9 ft) or even more as the emperor’s height. These figures usually come from body length rather than true standing height. A bird can briefly look taller when it stretches its neck to call or display, but day to day an emperor is about the height of a young child.

How much does an emperor penguin weigh?

Adult emperor penguins weigh about 22–45 kg (49–99 lb). The range is wide because weight changes so much with the breeding cycle. Birds fatten up at sea in late summer and autumn, then live off their reserves for weeks or months on the ice.

Even at its lightest, an emperor is one of the heaviest birds alive. Only a few large flightless ratites, such as ostriches, emus and cassowaries, are heavier.

How much weight do emperor penguins lose?

Males go through the hardest fast. A male walks to the colony in March or April, courts a female, and then incubates the egg on his feet through the dark winter. He does not eat for about 115–120 days in total.

During this fast, a male can lose up to about 40% of his body weight, typically 10–20 kg (22–44 lb). Huddling with other males in the cold helps him burn less energy and lose weight more slowly. Females also lose a lot while producing the egg, then regain it at sea while the males are fasting.

When the females return to take over the newly hatched chick, the thin males head straight for the sea. They spend about three to four weeks feeding before returning to share chick care.

Males vs females

Male and female emperor penguins are very similar in size and plumage. There is no obvious difference in height, and even experienced researchers often rely on calls or behavior to tell them apart. Males are usually heavier at the same point in the season, partly because they must build up larger reserves for the winter fast.

How does the emperor compare with other penguins?

Penguins range from the little penguin, about 30–33 cm (12–13 in) tall and around 1–1.5 kg (2–3 lb), up to the emperor. The king penguin is a clear second, standing about 70–100 cm (28–39 in) and weighing 9–18 kg (20–40 lb).

The pattern fits a general rule in biology: larger bodies lose heat more slowly relative to their size. The two biggest penguins live in the coldest places, while most small species live in milder waters. See how many penguin species there are for the full line-up.

Why do emperor penguins look short-legged?

An emperor penguin’s legs are not as short as they look. The thigh bone and knee are tucked inside the body, under feathers and a thick layer of fat, and only the lower leg and feet show. This posture gives penguins their upright, waddling look. Find out more in do penguins have knees?

Were there penguins as tall as people?

Yes. Millions of years ago, some penguins were much larger than any living species. Anthropornis nordenskjoeldi, known from fossils on Seymour Island, Antarctica, dating from roughly 40 million years ago, is estimated to have stood about 1.7–1.8 m (5.6–5.9 ft) tall. Kumimanu fordycei, described in 2023 from New Zealand fossils about 57 million years old, may have weighed around 150 kg (330 lb), several times as much as an emperor.

These sizes are estimates from partial skeletons, so scientists give them as ranges. But they show that the emperor, impressive as it is, is a small giant compared with some of its ancestors.