Usually they are ready to process at 7 to 9 weeks of age, but Meyers sent a new breed or something, because they have not filled out yet after 4 months ! I got them in the mail on October 12, 2012Last summer I bought 2 Cornish X White rocks. And in 6 months. They weighted 20lbs and 23lbs. Btw. I didn't know what they were, just that they were white. I have found out you raise the for bout 2 months just for meat birds.