Why are there no 20 generation genealogy charts?

Why are there no 20 generation genealogy charts?

"Do you have a genealogy chart that goes back 20 generations?" We get questions like this all the time. The answer, unfortunately, is "no."

The reason: math.

You have two parents, four grandparents, eight great-grandparents, and so on, doubling every generation. Our biggest chart covers 10 generations, including the children of the root person and spouse, with numbered spaces for 1,024 names. It requires a single sheet of paper nearly 2 feet wide by 3 feet tall unfolded, as shown below:

why no 20 generation charts
At 20 generations, you are looking at over a million ancestors (2^20, or 1,048,576 people). Even if you could do all the research, there is no genealogy chart big enough to include spaces for a million names. It would be thousands of feet tall!

Truth be told, the number of ancestors going back 20 generations (500-600 years on most lines) wouldn't be exactly 1,048,576 different people. That's because many lines criss-cross. Distant cousins marry, or communities are genetically concentrated because of language, religion, geography, or other reasons.

Nevertheless, there is a tremendous amount of variation within everyone's tree the further back you go. With hundreds of thousands of ancestors at the 20 generation mark, peasants, nobles, soldiers, weavers, butchers, sailors, and pancake makers will all have a place on your tree!

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