Ahnentafel Numbering System

The word "Ahnentafel" is a German word meaning "ancestor table", made up of the German words "Ahnen", meaning ancestors, and "Tafel", for table.

The Ahnentafel is a method for displaying information about one's ancestors. Its advantage is that it allows for a very concise display of information, able to show many ancestors at a glance.

To find the father of any person, double that number. To find the mother, double the number and add one. Other than the starting person, males always have even numbers and women odd numbers.

Using this system, you quickly notice some patterns. First, each new generation has double the number of ancestors of the previous generation. Thus you have four grandparents, eight great-grandparents, 16 great-great-grandparents and so on:

2-3 Parents (2)

4-7 Grandparents (4)

8-15 Great Grandparents (8)

16-31 Great Great Grandparents (16)

32-63 Great Great Great Grandparents (32)

64-127 Great Great Great Great Grandparents (64)

128-257 Great Great Great Great Great Grandparents (128)

etc