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
- 3 Your mother
- 6 Your mother's father
- 13 Your mother's father's mother
- 27 Your mother's father's mother's mother
- 54 Your mother's father's mother's mother's father
- 109 Your mother's father's mother's mother's father's mother
- 219 Your mother's father's mother's mother's father's mother's mother
- 438 Your mother's father's mother's mother's father's mother's mother's father
- 877 Your mother's father's mother's mother's father's mother's mother's father's mother
- 1755 Your mother's father's mother's mother's father's mother's mother's father's mother's mother
- 3510 Your mother's father's mother's mother's father's mother's mother's father's mother's mother's father
- 7021 Your mother's father's mother's mother's father's mother's mother's father's mother's mother's father's mother
- 14043 Your 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
- 28087 Your 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
- 56175 Your 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
- 112351 Your 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
- 224703 Your 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 mother
- 449406 Your 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 mother's father
- 898813 Your 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 mother's father's mother
- 1797627 Your 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 mother's father's mother's mother
- 3595255 Your 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 mother's father's mother's mother's mother
- 7190510 Your 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 mother's father's mother's mother's mother's father
- 14381021 Your 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 mother's father's mother's mother's mother's father's mother
- 28762043 Your 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 mother's father's mother's mother's mother's father's mother's mother
- 57524086 Your 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 mother's father's mother's mother's mother's father's mother's mother's father
- 115048173 Your 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 mother's father's mother's mother's mother's father's mother's mother's father's mother
- 230096347 Your 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 mother's father's mother's mother's mother's father's mother's mother's father's mother's mother
Your 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 mother's father's mother's mother's mother's father's mother's mother's father's mother's mother, a 25x great-grandmother, is number 230096347.