They can be as long as 41 feet (12.3 metres) in length, and weigh as much as 47,000 pounds (21.5 tonnes). However, it is believed that there are some whale sharks which can reach lengths of up to 67 feet (20 metres). The smallest free-living individuals are around 55 cm (21.7 inches) long. Whale sharks reach maturity at lengths of around 8–9 metres 