Ancestor Numbers
An Ancestor Number (the proper name is an Ahnentafel number) says exactly where a direct ancestor sits in your family tree. You are always number 1. Anyone's father has double their number, and their mother double plus one: so your father is 2 and your mother 3, your father's parents are 4 and 5, your mother's parents 6 and 7, and so on. That's why every man in your tree (apart from you) has an even number and every woman an odd one.
Entering the Ancestor Numbers of your direct ancestors on My Ancestors keeps your records accurate, helps your cousins work out how they're related to you, and tells apart two lines that happen to share a surname.
Print our Ancestor Chart Every box on the chart shows its number, five generations back from you.
Peter Calver, who founded LostCousins, explained Ancestor Numbers in his newsletter of 25 December 2023 (Why are your female ancestors odd?).
Find a number by stepping back from you
Choose father or mother, one generation at a time, until you reach the person you want.
- 1 You
- 2 Your father
- 5 Your father's mother
- 11 Your father's mother's mother
- 22 Your father's mother's mother's father
- 44 Your father's mother's mother's father's father
- 89 Your father's mother's mother's father's father's mother
- 179 Your father's mother's mother's father's father's mother's mother
- 359 Your father's mother's mother's father's father's mother's mother's mother
- 719 Your father's mother's mother's father's father's mother's mother's mother's mother
- 1439 Your father's mother's mother's father's father's mother's mother's mother's mother's mother
- 2879 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother
- 5758 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father
- 11516 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father
- 23033 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother
- 46067 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother
- 92134 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father
- 184269 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother
- 368538 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother's father
- 737076 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother's father's father
- 1474152 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother's father's father's father
- 2948304 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother's father's father's father's father
- 5896609 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother's father's father's father's father's mother
- 11793218 Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother's father's father's father's father's mother's father
Your father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's mother's father's father's father's father's mother's father, a 21x great-grandfather, is number 11793218.