The total time needed to boil eggs is between 20 and30 minutes. Hard-boiled eggs require 12 minutes of cooking time after the water begins to boil.
The time it takes for cold water to boil is approximately 10 to 20 minutes depending on altitude, saline content in the water and temperature of the stove. Boiling a smaller pot of eggs takes less time than a larger pot. To hard-boil eggs, the eggs are placed in a pot, covered with cold water and heated until boiling. Then the pot is removed from the heat and covered for 12 minutes. The eggs should be transferred to cold water for two minutes, then peeled.