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 (opens in a new tab) 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
- 95 Your father's mother's mother's mother's mother's mother
- 191 Your father's mother's mother's mother's mother's mother's mother
- 382 Your father's mother's mother's mother's mother's mother's mother's father
- 764 Your father's mother's mother's mother's mother's mother's mother's father's father
- 1528 Your father's mother's mother's mother's mother's mother's mother's father's father's father
- 3057 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother
- 6115 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother
- 12230 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father
- 24461 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother
- 48923 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother
- 97846 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father
- 195692 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father
- 391385 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother
- 782771 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother
- 1565543 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother
- 3131087 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother
- 6262175 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's mother
- 12524351 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's mother's mother
- 25048703 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's mother
- 50097407 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother
- 100194814 Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother's father
Your father's mother's mother's mother's mother's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother's father, a 24x great-grandfather, is number 100194814.