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
- 14 Your mother's mother's father
- 28 Your mother's mother's father's father
- 56 Your mother's mother's father's father's father
- 113 Your mother's mother's father's father's father's mother
- 227 Your mother's mother's father's father's father's mother's mother
- 455 Your mother's mother's father's father's father's mother's mother's mother
- 911 Your mother's mother's father's father's father's mother's mother's mother's mother
- 1822 Your mother's mother's father's father's father's mother's mother's mother's mother's father
- 3645 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother
- 7291 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother
- 14583 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother
- 29167 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother
- 58334 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's father
- 116669 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother
- 233339 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother
- 466679 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother
- 933359 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother
- 1866719 Your mother's mother's father's father's father's mother's mother's mother's mother's father's mother's mother's mother's mother's father's mother's mother's mother's mother's mother
- 3733439 Your mother's mother's father's father's father's mother's mother's mother'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
- 7466879 Your mother's mother's father's father's father's mother's mother's mother'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 mother
- 14933759 Your mother's mother's father's father's father's mother's mother's mother'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 mother's mother
Your mother's mother's father's father's father's mother's mother's mother'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 mother's mother, a 21x great-grandmother, is number 14933759.