Ahnentafel Numbering System

From a German word meaning "ancestor table," an ahnentafel is an ancestor based numbering system. An excellent choice for presenting a lot of information in a compact format.

What is an Ahnentafel?: An ahnentafel is basically a list of all known ancestors of a specific individual. Ahnentafel charts use a strict numbering scheme which makes it easy to see, at a glance, how a specific ancestor is related to the root individual. They also include the full name, and dates and places of birth, marriage and death for each listed individual (when known).

How to Read an Ahnentafel: The key to reading an ahnentafel is to understand its numbering system. Basically, you double any individual's number to get his/her father's number, and double a person's number and add one to get his/her mother's number. On your ahnentafel chart, you would be number 1. Your father, would then be number 2 (your number * 2 -> 1*2=2), and your mother, number 3 (1*2+1=3). Other than the starting person, males always have even numbers and women the odd numbers.

What Does an Ahnentafel Chart Look Like?:
To look at it visually, here is the layout of a typical ahnentafel chart, with the mathmatical numbering system illustrated:

1. person
2. father (1*2)
3. mother (1*2+1)
4. paternal grandfather (2*2)
5. paternal grandmother (2*2+1)
6. maternal grandfather (4*2)
7. maternal grandmother (4*2+1)
8. paternal grandfather's father - great grandfather (4*2)
9. paternal grandfather's mother - great grandmother (4*2+1)
10. paternal grandmother's father - great grandfather (5*2)
11. paternal grandmother's mother - great grandmother (5*2+1)
12. maternal grandfather's father - great grandfather (6*2)
13. maternal grandfather's mother - great grandmother (6*2+1)
14. maternal grandmother's father - great grandfather (7*2)
15. maternal grandmother's mother - great grandmother (7*2+1)

You may notice that the numbers used here are exactly the same as you're used to seeing in a pedigree chart. It is just presented in a more condensed, list format. Unlike the brief example shown here, a true ahnentafel will list each individual's full name, and dates and places of birth, marriage and death (if known).

You can create an ahnentafel chart by hand or produce it with your genealogy software program (where you may see it referred to as an ancestor chart. The ahnentafel is great for sharing because it only lists direct line ancestors, and presents them in a compact format that is easy to read.