How big can a pet land hermit crab get?

Land hermit crabs can vary in size depending on the species. The largest species of land hermit crab is the Coenobita brevimanus, which can reach a body size of up to 6.5 inches (16.5 cm). However, most pet land hermit crabs are smaller, with the most common species being the Coenobita clypeatus, which typically reaches a body size of around 2 inches (5 cm).