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
- 12 Your mother's father's father
- 24 Your mother's father's father's father
- 49 Your mother's father's father's father's mother
- 99 Your mother's father's father's father's mother's mother
- 199 Your mother's father's father's father's mother's mother's mother
- 398 Your mother's father's father's father's mother's mother's mother's father
- 797 Your mother's father's father's father's mother's mother's mother's father's mother
- 1595 Your mother's father's father's father's mother's mother's mother's father's mother's mother
- 3191 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother
- 6383 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother
- 12767 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother
- 25535 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother
- 51070 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father
- 102140 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father
- 204280 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father
- 408561 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother
- 817123 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother
- 1634247 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother
- 3268495 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother
- 6536991 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother
- 13073983 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's mother
- 26147966 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's mother's father
- 52295932 Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's mother's father's father
Your mother's father's father's father's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's mother's father's father, a 23x great-grandfather, is number 52295932.