Blaine Bettinger is a well-know genetic genealogist. He has done a fantastic job of collecting data to help us understand our DNA matches better. Yesterday, I posted about the Shared cM project in which Blaine has collected DNA information from thousands of participants in order to create a chart showing the range of shared cM numbers for each relationship.


One of the ways that he collects this data is through a Google form that is open to anyone who has completed dna testing. You can help further this project by adding your own data for KNOWN RELATIONSHIP MATCHES to the project. Blaine updates this chart whenever he has a significant amount of new data.

Today’s snack: look up the number of shared cMs you have for at least 1 known ancestor and contribute that number to the project. You can fill in the form for as many known matches as you have.

Before you go to the form, you’ll need the following information:

  • The relationship between the two matched individuals (brother/sister, aunt/nephew, 1C1R, etc.)
  • Total shared cM
  • Number of shared segments
  • Any known endogamy or known cousin marriages? (yes/no)
  • Source of the dna test

Optional information includes:

  • Number of cM in the longest block (this data is not available through AncestryDNA)
  • Any notes you’d like to include about a special relationship
  • Your email so that he can contact you if you have questions.

Click on the link below to contribute to the project!

Shared cM Project