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
- 1438 Your father's mother's mother's father's father's mother's mother's mother's mother's father
- 2877 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother
- 5755 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother
- 11511 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother
- 23023 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother
- 46047 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother
- 92095 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother
- 184191 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother
- 368382 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father
- 736765 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother
- 1473531 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother
- 2947062 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father
- 5894125 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother
- 11788251 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother's mother
- 23576503 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother
- 47153007 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's mother
- 94306015 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's mother's mother
- 188612031 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's mother's mother's mother
- 377224062 Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's mother's mother's mother's father
Your father's mother's mother's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's mother's mother's mother's father, a 26x great-grandfather, is number 377224062.