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
- 15 Your mother's mother's mother
- 30 Your mother's mother's mother's father
- 60 Your mother's mother's mother's father's father
- 121 Your mother's mother's mother's father's father's mother
- 242 Your mother's mother's mother's father's father's mother's father
- 484 Your mother's mother's mother's father's father's mother's father's father
- 969 Your mother's mother's mother's father's father's mother's father's father's mother
- 1938 Your mother's mother's mother's father's father's mother's father's father's mother's father
- 3876 Your mother's mother's mother's father's father's mother's father's father's mother's father's father
- 7752 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father
- 15505 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother
- 31011 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother
- 62023 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother's mother
- 124047 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother's mother's mother
- 248094 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother's mother's mother's father
- 496188 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother's mother's mother's father's father
- 992376 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother's mother's mother's father's father's father
- 1984752 Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother's mother's mother's father's father's father's father
Your mother's mother's mother's father's father's mother's father's father's mother's father's father's father's mother's mother's mother's mother's father's father's father's father, a 18x great-grandfather, is number 1984752.