Most humans as they currently are may need 16 years to grow an adult size limb, but it doesn't need to be that way. An interesting question would be how long d

Most humans as they currently are may need 16 years to grow an adult size limb, but it doesn't need to be that way. An interesting question would be how long does it take a baby to gain the mass of a limb? Another interesting question would be how fast can an adult gain weight? Another interesting question would be if it takes a person 18 years to reach 6' and 160lbs and then they stop growing, how long would it take them to grow another foot or two if they didn't stop growing?