What is the heaviest penguin?
The emperor penguin is the heaviest penguin species, with adults weighing between 22 and 45 kg (49 to 99 pounds). Their weight fluctuates dramatically throughout the year — males reach peak weight before the breeding season, then lose up to 12 kg during their two-month incubation fast. The king penguin is the second heaviest at 11 to 16 kg. At the other extreme, the little blue penguin weighs just 1 to 1.5 kg. Emperor penguin chicks can weigh up to 15 kg before they fledge, which is heavier than some adult penguins of other species.
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Reference bodies behind our comparison answers. Links last checked August 5, 2026.
- IUCN Red List - Global conservation assessments and extinction-risk categories.
- BirdLife Data Zone - Species accounts, distribution, and population summaries.
- Smithsonian Ocean Portal - Penguin biology, anatomy, and breeding explainers.