How big do crustaceans grow?

There is a wide range in the size of crustaceans.  Many don’t grow bigger than about 0.25 mm (0.01 inches) and others grow to enormous proportions, reaching several kilograms (pounds) in weight.  The largest known crustaceans are the Japanese spider crab, with a leg span of 4 m (13 feet); the Alaskan king crab, weighing in at 10 kg (22 pounds); and the giant Tasmanian crab, weighing in at a whopping 14 kg (31 pounds).