Fully grown chickens

[cravenchx]

Don't know if this is the right place to post, but....
When are chickens considered fully grown?

 

[Ukiah]

Most will reach maturity around 5-6 months of age.
However they will continue to grow and put on weight until they are 19-20 months.

 

[cmom]

A chicken is actually fully grown at about 6 months old. Female chickens are called pullets up to their first year. After the first year they are called hens.