What age do chickens start to lay?

most start around 18 weeks(41/2 months) so you still have some time, your production (leghorn/redstar/blackstars) will usually start sooner by a couple of weeks, and your bigger breeds Orps/brahma's usually start a couple weeks later,(sometimes a couple months later)

 

i have barred rocks and black stars that are 4 months old and they havent started laying yet i put litter in my laying boxes and put a few golf balls in to "promote" laying and they havent even considered laying from what i can tell

 

Hi Someone else asked a similiar question a few weeks ago and one of the more interesting answers was - "a few weeks after the roosters hit puberty (i.e. try to mate) you can expect the pullets to start laying". I guess the boys mature a little sooner than the girls