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
- 119 Your mother's mother's father's mother's mother's mother
- 238 Your mother's mother's father's mother's mother's mother's father
- 477 Your mother's mother's father's mother's mother's mother's father's mother
- 955 Your mother's mother's father's mother's mother's mother's father's mother's mother
- 1910 Your mother's mother's father's mother's mother's mother's father's mother's mother's father
- 3821 Your mother's mother's father's mother's mother's mother's father's mother's mother's father's mother
- 7643 Your mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother
- 15286 Your 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
- 30573 Your 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
- 61147 Your 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
- 122294 Your 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
- 244589 Your 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 mother
- 489179 Your 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 mother's mother
- 978359 Your 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 mother's mother's mother
- 1956719 Your 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 mother's mother's mother's mother
- 3913439 Your 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 mother's mother's mother's mother's mother
- 7826878 Your 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 mother's mother's mother's mother's mother's father
Your 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 mother's mother's mother's mother's mother's father, a 20x great-grandfather, is number 7826878.