The serving size of a deviled eggs is 2. Since each deviled egg is a half of an egg that is one hard boiled egg per person if you are planning 1 serving per person. Keep in mind when you are making your menu that some people will eat more than 1 serving and some won't eat any at all. I plan 3 deviled eggs per person. 6 people = 18 deviled eggs (9 hard boiled eggs) 10 people = 30 deviled eggs (15 hard boiled eggs) 12 people = 36 deviled eggs (18 hard boiled eggs) 16 people = 48 deviled eggs (24 hard boiled eggs) 20 people = 60 deviled eggs (30 hard boiled eggs)