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
- 47 Your father's mother's mother's mother's mother
- 94 Your father's mother's mother's mother's mother's father
- 189 Your father's mother's mother's mother's mother's father's mother
- 379 Your father's mother's mother's mother's mother's father's mother's mother
- 758 Your father's mother's mother's mother's mother's father's mother's mother's father
- 1516 Your father's mother's mother's mother's mother's father's mother's mother's father's father
- 3032 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father
- 6064 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father
- 12128 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father
- 24256 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father
- 48513 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father's mother
- 97027 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father's mother's mother
- 194055 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father's mother's mother's mother
- 388110 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father's mother's mother's mother's father
- 776221 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father's mother's mother's mother's father's mother
- 1552442 Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father's mother's mother's mother's father's mother's father
Your father's mother's mother's mother's mother's father's mother's mother's father's father's father's father's father's father's mother's mother's mother's father's mother's father, a 18x great-grandfather, is number 1552442.