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
- 47 Your father's mother's mother's mother's mother
- 95 Your father's mother's mother's mother's mother's mother
- 191 Your father's mother's mother's mother's mother's mother's mother
- 383 Your father's mother's mother's mother's mother's mother's mother's mother
- 767 Your father's mother's mother's mother's mother's mother's mother's mother's mother
- 1534 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father
- 3068 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father
- 6137 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother
- 12275 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother
- 24550 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father
- 49100 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father
- 98200 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father
- 196401 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother
- 392803 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother
- 785606 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father
- 1571213 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother
- 3142427 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother
- 6284854 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father
- 12569708 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father
- 25139416 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father
- 50278832 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father's father
- 100557664 Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father's father's father
Your father's mother's mother's mother's mother's mother's mother's mother's mother's father's father's mother's mother's father's father's father's mother's mother's father's mother's mother's father's father's father's father's father, a 24x great-grandfather, is number 100557664.