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
- 3 Your mother
- 7 Your mother's mother
- 14 Your mother's mother's father
- 29 Your mother's mother's father's mother
- 58 Your mother's mother's father's mother's father
- 116 Your mother's mother's father's mother's father's father
- 233 Your mother's mother's father's mother's father's father's mother
- 467 Your mother's mother's father's mother's father's father's mother's mother
- 935 Your mother's mother's father's mother's father's father's mother's mother's mother
- 1871 Your mother's mother's father's mother's father's father's mother's mother's mother's mother
- 3743 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother
- 7487 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother
- 14975 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother's mother
- 29951 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother
- 59902 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother's father
- 119805 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother's father's mother
- 239611 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother's father's mother's mother
- 479223 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's mother
- 958447 Your mother's mother's father's mother's father's father's mother's mother's mother's mother's mother's mother's mother's mother's father's mother's mother's mother's mother
- 1916895 Your mother's mother's father's mother's father's father's mother'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 mother
- 3833791 Your mother's mother's father's mother's father's father's mother'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 mother's mother
- 7667582 Your mother's mother's father's mother's father's father's mother'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 mother's mother's father
- 15335164 Your mother's mother's father's mother's father's father's mother'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 mother's mother's father's father
- 30670328 Your mother's mother's father's mother's father's father's mother'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 mother's mother's father's father's father
Your mother's mother's father's mother's father's father's mother'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 mother's mother's father's father's father, a 22x great-grandfather, is number 30670328.