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
- 31 Your mother's mother's mother's mother
- 62 Your mother's mother's mother's mother's father
- 125 Your mother's mother's mother's mother's father's mother
- 251 Your mother's mother's mother's mother's father's mother's mother
- 502 Your mother's mother's mother's mother's father's mother's mother's father
- 1004 Your mother's mother's mother's mother's father's mother's mother's father's father
- 2008 Your mother's mother's mother's mother's father's mother's mother's father's father's father
- 4017 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother
- 8035 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother
- 16070 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father
- 32140 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father
- 64280 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father
- 128561 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother
- 257123 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother
- 514246 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father
- 1028493 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother
- 2056987 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother
- 4113974 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father
- 8227949 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's mother
- 16455899 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's mother's mother
- 32911798 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's mother's mother's father
- 65823597 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother
- 131647195 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother
- 263294391 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father'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
- 526588782 Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father'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 father
Your mother's mother's mother's mother's father's mother's mother's father's father's father's mother's mother's father's father'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 father, a 26x great-grandfather, is number 526588782.