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
- 22 Your father's mother's mother's father
- 45 Your father's mother's mother's father's mother
- 91 Your father's mother's mother's father's mother's mother
- 183 Your father's mother's mother's father's mother's mother's mother
- 367 Your father's mother's mother's father's mother's mother's mother's mother
- 735 Your father's mother's mother's father's mother's mother's mother's mother's mother
- 1471 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother
- 2943 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother
- 5886 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father
- 11773 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother
- 23547 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother
- 47095 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's mother
- 94190 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's mother's father
- 188381 Your father's mother's mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's mother's father's mother
- 376763 Your father's mother's mother's father's mother'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
- 753527 Your father's mother's mother's father's mother'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 mother
- 1507055 Your father's mother's mother's father's mother'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 mother's mother
- 3014111 Your father's mother's mother's father's mother'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 mother's mother's mother
- 6028223 Your father's mother's mother's father's mother'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 mother's mother's mother's mother
- 12056446 Your father's mother's mother's father's mother'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 mother's mother's mother's mother's father
- 24112892 Your father's mother's mother's father's mother'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 mother's mother's mother's mother's father's father
- 48225785 Your father's mother's mother's father's mother'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 mother's mother's mother's mother's father's father's mother
- 96451571 Your father's mother's mother's father's mother'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 mother's mother's mother's mother's father's father's mother's mother
Your father's mother's mother's father's mother'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 mother's mother's mother's mother's father's father's mother's mother, a 24x great-grandmother, is number 96451571.