How big is a pirranaha?

Piranhas range in size from the tiny red-bellied piranha, which grows to only about 5 inches (13 centimeters) long, to the black piranha, which can grow to over 3 feet (1 meter) long and weigh more than 35 pounds (16 kilograms). Most piranhas, however, are less than 1 foot (30 centimeters) long.