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
- 1939 Your mother's mother's mother's father's father's mother's father's father's mother's mother
- 3879 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother
- 7759 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother
- 15519 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother
- 31038 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father
- 62077 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother
- 124155 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother's mother
- 248311 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother
- 496623 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother
- 993246 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father
- 1986493 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother
- 3972987 Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother
Your mother's mother's mother's father's father's mother's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother, a 19x great-grandmother, is number 3972987.