plz how long will take day old cockerel to mature?

thanx for the reply, i really appreciate u guys, but how about breed and sale? is it really okay as per business wise?

i just received three hundred day hold broilers but they re seven days old now, they have practically consume one bag of super starter feed, i have opened the second bag, with the way things re going now how many bags do i need to buy to sustain them till december.