The length of time it takes to hard boil an egg depends on the size and type of the egg. First, put eggs in a pan and fill with enough cold water to cover eggs completely, then bring water to a rapid boil. As soon as the water reaches a rapid boil, remove pan from heat and cover egg pan tightly with a lid. Let sit 12 minutes for regular-sized eggs, 17 minutes for large eggs and 20 minutes for jumbo eggs. Transfer eggs immediately to cold water and let cool at least 10 minutes. This causes a layer of steam to develop between the shell and the egg white, which makes peeling the egg much easier. Store in refrigerator.