A chicken egg takes approximately 24-26 hours to form from start to finish inside a hen's reproductive system. The process begins when a yolk is released from the ovary and enters the oviduct, where it travels through several distinct stages. As it moves through the oviduct, the egg white (albumen) is added, followed by the inner and outer shell membranes, and finally the hard calcium shell itself. The final stage, where the shell is deposited and hardened, takes about 20 hours. Once complete, the finished egg is laid. Hens typically lay one egg per day during their productive years, though this rate can vary based on breed, age, nutrition, light exposure, and overall health. Young hens in their prime laying years tend to be the most consistent egg producers. The timing also means that a hen will usually lay her eggs at roughly the same time each day, though the time gradually shifts later each subsequent day until eventually resetting.