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
- 3 Your mother
- 7 Your mother's mother
- 14 Your mother's mother's father
- 29 Your mother's mother's father's mother
- 59 Your mother's mother's father's mother's mother
- 119 Your mother's mother's father's mother's mother's mother
- 239 Your mother's mother's father's mother's mother's mother's mother
- 478 Your mother's mother's father's mother's mother's mother's mother's father
- 957 Your mother's mother's father's mother's mother's mother's mother's father's mother
- 1915 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother
- 3831 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother
- 7662 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father
- 15325 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother
- 30651 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother
- 61302 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father
- 122604 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father
- 245209 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother
- 490419 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother's mother
- 980839 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother's mother's mother
- 1961679 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother
- 3923358 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's father
- 7846717 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's father's mother
- 15693434 Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's father's mother's father
Your mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's father's mother's father, a 21x great-grandfather, is number 15693434.