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
- 55 Your mother's father's mother's mother's mother
- 111 Your mother's father's mother's mother's mother's mother
- 223 Your mother's father's mother's mother's mother's mother's mother
- 447 Your mother's father's mother's mother's mother's mother's mother's mother
- 895 Your mother's father's mother's mother's mother's mother's mother's mother's mother
- 1790 Your mother's father's mother's mother's mother's mother's mother's mother's mother's father
- 3581 Your mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother
- 7163 Your mother's father's mother's mother's mother's mother's mother's mother's mother's father's mother's mother
- 14327 Your 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
- 28655 Your 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 mother
- 57310 Your 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 mother's father
- 114620 Your 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 mother's father's father
- 229241 Your 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 mother's father's father's mother
- 458483 Your 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 mother's father's father's mother's mother
- 916966 Your 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 mother's father's father's mother's mother's father
- 1833932 Your 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 mother's father's father's mother's mother's father's father
- 3667865 Your 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 mother's father's father's mother's mother's father's father's mother
- 7335731 Your 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 mother's father's father's mother's mother's father's father's mother's mother
- 14671463 Your 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 mother's father's father's mother's mother's father's father's mother's mother's mother
Your 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 mother's father's father's mother's mother's father's father's mother's mother's mother, a 21x great-grandmother, is number 14671463.