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
- 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
- 108 Your mother's father's mother's mother's father's father
- 217 Your mother's father's mother's mother's father's father's mother
- 434 Your mother's father's mother's mother's father's father's mother's father
- 869 Your mother's father's mother's mother's father's father's mother's father's mother
- 1739 Your mother's father's mother's mother's father's father's mother's father's mother's mother
- 3479 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother
- 6959 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother
- 13918 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father
- 27837 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother
- 55675 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother
- 111351 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother's mother
- 222703 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother
- 445407 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother
- 890815 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother
- 1781630 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father
- 3563261 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's mother
- 7126523 Your mother's father's mother's mother's father's father's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother's mother's father's mother's mother
- 14253047 Your mother's father's mother's mother's father's father's mother's father's mother's mother'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
Your mother's father's mother's mother's father's father's mother's father's mother's mother'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, a 21x great-grandmother, is number 14253047.