Depends on size of egg, and if it's been stored in the fridge or room temp - add on at least half a minute if from the fridge.. And you can boil egg fROM cold water or place it in when a rolling boil, then simmer. I suggest from a rolling boil as depending on the heat, you can not be sure how long it will take for the egg to sit in the pan before reaching a boil.
4 minutes - soft yolk, but not "snotty" - all white is solid.
6 minutes - firmer, say, inner half of yolk soft - nice for sandwiches.
8 minutes - hard boiled.
Do not leave hard boiled in the pan of water as it cools - this can cause a nasty sulphur smell when shelling.
Take care with youngsters and the elderly or anyone vulnerable with soft eggs, as salmonella can be a problem for these groups.
Happy Easter, bunny!