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
- 368 Your father's mother's mother's mother's father's father's father's father
- 736 Your father's mother's mother's mother's father's father's father's father's father
- 1472 Your father's mother's mother's mother's father's father's father's father's father's father
- 2945 Your father's mother's mother's mother's father's father's father's father's father's father's mother
- 5891 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother
- 11783 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother
- 23567 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother
- 47134 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father
- 94268 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father's father
- 188537 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father's father's mother
- 377075 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father's father's mother's mother
- 754151 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father's father's mother's mother's mother
- 1508303 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father's father's mother's mother's mother's mother
- 3016606 Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father's father's mother's mother's mother's mother's father
Your father's mother's mother's mother's father's father's father's father's father's father's mother's mother's mother's mother's father's father's mother's mother's mother's mother's father, a 19x great-grandfather, is number 3016606.