It also depends on how old the eggs are. I can't remember the exact numbers, but I do know that the older the egg is, the more time it needs. This last batch I did was in a forced-air hovabator, and it went fairly easily. I think the ones I got from Tori were all done in a still air LG, and I had 1 or 2 hatch the first day, the majority hatch the second day, and 2 or 3 hatch the 3rd day. I waited 2 days after that, and opened the eggs. Most of the others either weren't developed or had died late in development.