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
- 14 Your mother's mother's father
- 29 Your mother's mother's father's mother
- 59 Your mother's mother's father's mother's mother
- 118 Your mother's mother's father's mother's mother's father
- 237 Your mother's mother's father's mother's mother's father's mother
- 475 Your mother's mother's father's mother's mother's father's mother's mother
- 951 Your mother's mother's father's mother's mother's father's mother's mother's mother
- 1902 Your mother's mother's father's mother's mother's father's mother's mother's mother's father
- 3804 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father
- 7609 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother
- 15219 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother
- 30438 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father
- 60876 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father's father
- 121752 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father's father's father
- 243504 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father's father's father's father
- 487009 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father's father's father's father's mother
- 974019 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father's father's father's father's mother's mother
- 1948038 Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father's father's father's father's mother's mother's father
Your mother's mother's father's mother's mother's father's mother's mother's mother's father's father's mother's mother's father's father's father's father's mother's mother's father, a 18x great-grandfather, is number 1948038.