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
- 190 Your father's mother's mother's mother's mother's mother's father
- 380 Your father's mother's mother's mother's mother's mother's father's father
- 760 Your father's mother's mother's mother's mother's mother's father's father's father
- 1521 Your father's mother's mother's mother's mother's mother's father's father's father's mother
- 3043 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother
- 6087 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother
- 12175 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother
- 24351 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother
- 48702 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father
- 97405 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father's mother
- 194811 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father's mother's mother
- 389623 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother
- 779246 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's father
- 1558492 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's father's father
- 3116985 Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's father's father's mother
Your father's mother's mother's mother's mother's mother's father's father's father's mother's mother's mother's mother's mother's father's mother's mother's mother's father's father's mother, a 19x great-grandmother, is number 3116985.