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
- 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
- 567 Your father's father's father's mother's mother's father's mother's mother's mother
- 1135 Your father's father's father's mother's mother's father's mother's mother's mother's mother
- 2270 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father
- 4541 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother
- 9083 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother
- 18166 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother's father
- 36333 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother's father's mother
- 72667 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother's father's mother's mother
- 145335 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother
- 290670 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's father
- 581341 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother
- 1162683 Your father's father's father's mother's mother's father's mother's mother's mother's mother's father's mother's mother's father's mother's mother's mother's father's mother's mother
- 2325367 Your father's father's father's mother's mother's father's mother's mother'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 mother
- 4650735 Your father's father's father's mother's mother's father's mother's mother'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 mother's mother
- 9301471 Your father's father's father's mother's mother's father's mother's mother'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 mother's mother's mother
- 18602943 Your father's father's father's mother's mother's father's mother's mother'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 mother's mother's mother's mother
- 37205886 Your father's father's father's mother's mother's father's mother's mother'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 mother's mother's mother's mother's father
- 74411772 Your father's father's father's mother's mother's father's mother's mother'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 mother's mother's mother's mother's father's father
Your father's father's father's mother's mother's father's mother's mother'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 mother's mother's mother's mother's father's father, a 24x great-grandfather, is number 74411772.