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
- 6 Your mother's father
- 13 Your mother's father's mother
- 26 Your mother's father's mother's father
- 52 Your mother's father's mother's father's father
- 104 Your mother's father's mother's father's father's father
- 209 Your mother's father's mother's father's father's father's mother
- 419 Your mother's father's mother's father's father's father's mother's mother
- 838 Your mother's father's mother's father's father's father's mother's mother's father
- 1676 Your mother's father's mother's father's father's father's mother's mother's father's father
- 3352 Your mother's father's mother's father's father's father's mother's mother's father's father's father
- 6705 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother
- 13411 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother
- 26822 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father
- 53645 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother
- 107291 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother
- 214582 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father
- 429164 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father
- 858328 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father
- 1716657 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father's mother
- 3433314 Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father's mother's father
Your mother's father's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father's mother's father, a 19x great-grandfather, is number 3433314.