---> My <--- method for sexing young chicks. I've tried this method many times and it proves around 95% correct. I've even marked the chicks legs from previous hatches, just so I could keep track.
If you take a young chicken chick in your hand, flip it on its back and wait a couple of seconds, for it to settle down. If the chick pulls both of it's feet up tight, it's a hen. If it extends even one leg, it's a roo. Although most roos extend both legs out straight.
This chick is a hen, notice it's feet are pulled up tight to its adomen. I must have fished out 50 chicks from those tubs, looking for hens.
Turkey chicks are the exact opposite. Hens extend their legs and roos pull their legs up tight.
Please note... I have no formal chicken/turkey education. This is just my trial and error experiences, talking. I'm sure there are other ways to sex fowls, but this method seems to work well for me, it's pretty accurate.