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 (opens in a new tab) 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
- 45 Your father's mother's mother's father's mother
- 91 Your father's mother's mother's father's mother's mother
- 183 Your father's mother's mother's father's mother's mother's mother
- 367 Your father's mother's mother's father's mother's mother's mother's mother
- 735 Your father's mother's mother's father's mother's mother's mother's mother's mother
- 1471 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother
- 2943 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother
- 5887 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's mother
- 11775 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's mother's mother
- 23550 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's mother's mother's father
- 47101 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's mother's mother's father's mother
- 94203 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's mother's mother's father's mother's mother
- 188406 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father
- 376813 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's father's mother
- 753627 Your father's mother's mother's father's mother's mother'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
- 1507255 Your father's mother's mother's father's mother's mother'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
- 3014511 Your father's mother's mother's father's mother's mother'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
- 6029022 Your father's mother's mother's father's mother's mother'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 father
- 12058044 Your father's mother's mother's father's mother's mother'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 father's father
- 24116089 Your father's mother's mother's father's mother's mother'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 father's father's mother
- 48232179 Your father's mother's mother's father's mother's mother'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 father's father's mother's mother
- 96464359 Your father's mother's mother's father's mother's mother'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 father's father's mother's mother's mother
- 192928719 Your father's mother's mother's father's mother's mother'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 father's father's mother's mother's mother's mother
- 385857438 Your father's mother's mother's father's mother's mother'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 father's father's mother's mother's mother's mother's father
Your father's mother's mother's father's mother's mother'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 father's father's mother's mother's mother's mother's father, a 26x great-grandfather, is number 385857438.