Usually an average chicken will lay one egg per day, but this varies from time of the year and from breed to breed. Some breeds have 2 eggs a day in their egg season. So probably you'll need 20 chickens, 10 for the egg laying season of winter through spring and 10 for the egg laying season of summer to fall.
If you are raising specifically for a year round supply of eggs, make sure you get a winter hearty breed, or provide extra heat and artificial light during the winter. In Southern states, the Orpington chickens (Buff, Black, and White) tend to lay year round, though not as prolifically as their average one egg a day in their first summer of laying.
About ten or fifteen chickens
hope this helps!
hope this helps!