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
- 4 Your father's father
- 8 Your father's father's father
- 17 Your father's father's father's mother
- 35 Your father's father's father's mother's mother
- 70 Your father's father's father's mother's mother's father
- 141 Your father's father's father's mother's mother's father's mother
- 283 Your father's father's father's mother's mother's father's mother's mother
- 566 Your father's father's father's mother's mother's father's mother's mother's father
- 1133 Your father's father's father's mother's mother's father's mother's mother's father's mother
- 2267 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother
- 4534 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father
- 9069 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother
- 18139 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother
- 36279 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother
- 72558 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father
- 145117 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother
- 290235 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother
- 580470 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father
- 1160941 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother
- 2321883 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother
- 4643766 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father
- 9287532 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father
- 18575065 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father's mother
- 37150131 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father's mother's mother
- 74300262 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father's mother's mother's father
- 148600525 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father's mother's mother's father's mother
- 297201051 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father's mother's mother's father's mother's mother
- 594402102 Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father's mother's mother's father's mother's mother's father
Your father's father's father's mother's mother's father's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother's father's mother's mother's father's father's mother's mother's father's mother's mother's father, a 27x great-grandfather, is number 594402102.