three minutes approx. An average-sized hen's egg takes roughly three minutes to cook in water, thus most conventional egg clocks have that as their preset time. Eggs that are hard-boiled take longer to cook. Soft-boiled eggs are timed for three minutes.
Simply fill the bottom of a pan with eggs in a single layer. Add at least two inches of room-temperature water on top. Set timer on egg timer, based on how you want your eggs, hard boiled or soft boiled. Once the timer is done, your eggs will be boiled as you like it.