What is the average length of a newborn humpback whale?

The average length of a newborn humpback whale is about 4.5 meters. That is roughly the length of a large car, yet the calf is only the first stage of a life that may eventually produce an animal more than 14 meters long and weighing up to 40 metric tons.

Humpback calves are usually born in warm tropical or subtropical breeding waters after a gestation of about 11 to 12 months. A mother generally gives birth to a single calf and helps it reach the surface for its first breath. Newborns commonly weigh around 680 to 1,800 kilograms, depending on the population and source.

The calf drinks its mother’s exceptionally rich milk and grows rapidly. Nursing can continue for about a year, although young humpbacks may begin taking solid food at roughly six months. The 4.5-meter figure is an average, so individual calves may be somewhat shorter or longer. This is why ranges such as 4–5 meters also appear in whale references.