Instructions
Determine the breed of your chicken. If you can find pictures of hens and roosters of that particular breed, you will find it easier to determine the sex.
Look at the tail feathers. Hens tend to have shorter, stiffer tail feathers, while roosters have longer tail feathers that arch into a big plumage.
Check the size of the comb. A rooster generally has a large comb on top of his head, and a wattle hanging below the beak. Hens have smaller combs, which sit close to the head, or even no pronounced comb at all.
Notice the neck feathers. A rooster's neck feathers are usually long, and he will puff them out when provoked. A hen's neck feathers are typically short and sit close to the neck in a smooth line.
Listen to the birds. Roosters crow loudly, especially at dawn and dusk. Hens make 'clucking' noises.
Check the nest. If you have a hen, chances are good there will be some eggs in the nesting area, especially if she is over 6 months old.
How to Tell the Difference Between a Hen & Rooster
There are hundreds of breeds of chickens, and in each breed, the hens and roosters usually look very different. Even a young hen, called a pullet, and a young rooster, called a cockerel, will be easily distinguished as either male or female. As with many animal and bird species, the male is showier, larger and makes more noise.