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
- 366 Your father's mother's mother's father's mother's mother's mother's father
- 733 Your father's mother's mother's father's mother's mother's mother's father's mother
- 1467 Your father's mother's mother's father's mother's mother's mother's father's mother's mother
- 2934 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father
- 5869 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother
- 11739 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother
- 23478 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father
- 46957 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother
- 93915 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother
- 187830 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father
- 375660 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father
- 751320 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father
- 1502641 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother
- 3005283 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother
- 6010566 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father
- 12021133 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother
- 24042267 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother
- 48084535 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother's mother
- 96169071 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother's mother's mother
- 192338142 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother's mother's mother's father
- 384676284 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother's mother's mother's father's father
- 769352568 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother's mother's mother's father's father's father
- 1538705136 Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother's mother's mother's father's father's father's father
Your father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's father's father's father's mother's mother's father's mother's mother's mother's mother's father's father's father's father, a 28x great-grandfather, is number 1538705136.