For large eggs, cover them with about 1 inch of cold water in a single layer, bring the water just to a boil, then remove the pan from the heat, cover it, and let the eggs stand about 12 minutes (about 9 minutes for medium eggs and about 15 minutes for extra-large).
Drain them right away and serve warm, or cool under cold running water or in ice water before refrigerating. Cook until both the white and yolk are firm; refrigerate hard-cooked eggs within 2 hours and use within a week.
Source: How to Make Hard Boiled Eggs — American Egg Board / Incredible Egg