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
- 2 Your father
- 5 Your father's mother
- 11 Your father's mother's mother
- 23 Your father's mother's mother's mother
- 46 Your father's mother's mother's mother's father
- 92 Your father's mother's mother's mother's father's father
- 184 Your father's mother's mother's mother's father's father's father
- 369 Your father's mother's mother's mother's father's father's father's mother
- 739 Your father's mother's mother's mother's father's father's father's mother's mother
- 1478 Your father's mother's mother's mother's father's father's father's mother's mother's father
- 2956 Your father's mother's mother's mother's father's father's father's mother's mother's father's father
- 5913 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother
- 11827 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother
- 23655 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother
- 47311 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother
- 94622 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother's father
- 189244 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother's father's father
- 378488 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother's father's father's father
- 756976 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother's father's father's father's father
- 1513953 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother's father's father's father's father's mother
- 3027907 Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother's father's father's father's father's mother's mother
Your father's mother's mother's mother's father's father's father's mother's mother's father's father's mother's mother's mother's mother's father's father's father's father's mother's mother, a 19x great-grandmother, is number 3027907.