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
- 23 Your father's mother's mother's mother
- 47 Your father's mother's mother's mother's mother
- 95 Your father's mother's mother's mother's mother's mother
- 190 Your father's mother's mother's mother's mother's mother's father
- 381 Your father's mother's mother's mother's mother's mother's father's mother
- 763 Your father's mother's mother's mother's mother's mother's father's mother's mother
- 1527 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother
- 3055 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother
- 6110 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father
- 12221 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother
- 24443 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother
- 48887 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother
- 97775 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother
- 195551 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother
- 391103 Your father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother
- 782206 Your father's mother's mother's mother's mother's mother'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 father
- 1564413 Your father's mother's mother's mother's mother's mother'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 father's mother
- 3128826 Your father's mother's mother's mother's mother's mother'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 father's mother's father
- 6257653 Your father's mother's mother's mother's mother's mother'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 father's mother's father's mother
Your father's mother's mother's mother's mother's mother'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 father's mother's father's mother, a 20x great-grandmother, is number 6257653.