My Most Used Genealogy Tool: DNA Painter’s Shared cM Project Tool

Best Genealogy Tool for DNA Matches: DNA Painter’s Shared cM Project Tool

​When it comes to genealogy, I find myself consistently relying on one invaluable tool: DNA Painter’s Shared cM Project tool. This tool, developed by genetic genealogist Blaine Bettinger and hosted on DNA Painter, has become essential for mapping out DNA match relationships, whether in my personal family research or client cases. The Shared cM Project tool is simple in design, yet it offers powerful insights by estimating the range of possible relationships between DNA matches based on the number of shared centimorgans (cM).

Why I Use the Shared cM Project Tool So Often

Genealogical research is often like solving a complex puzzle where relationships and connections can be tricky to pin down, especially when it involves unknown parentage or unknown ancestors. When I’m working with DNA test results, whether for my family history or a client’s case, the Shared cM Project tool helps guide my analysis. It’s especially useful when I need to hypothesize the possible relationships between DNA matches and where they fit in, such as estimating whether someone is a likely second cousin, third cousin, or even further removed.

How the Shared cM Project Tool Works

The Shared cM Project tool works by allowing you to enter the amount of DNA (in centimorgans) shared with a particular match. Based on this input, the tool suggests a variety of possible relationships between you and the DNA match, along with the relationship probabilities (%) and a chart for those who are more visual, using data collected from thousands of known relationships. For example:

• If a DNA match shares around 50 cM with you, the tool will suggest that this person could be a potential half-third cousin (Half 3c) or even a half-second cousin twice removed (Half 2c2r), along with many more possible relationships.

DNA Painter Shared cM Project Tool- Example 1-1

DNA Painter Shared cM Project Tool- Example 1-2

• For higher shared cM values, say 800 cM, the tool might suggest closer relationships like first cousin (1c) or half-aunt/uncle, along with a few others.

DNA Painter Shared cM Project Tool- Example 2-1

DNA Painter Shared cM Project Tool- Example 2-2

​In complex cases with multiple DNA matches, the tool’s ability to highlight likely relationships can make a big difference in narrowing down the family tree branches I need to explore.

Real-World Examples of DNA Painter’s Impact in My Research

One example where DNA Painter’s Shared cM Project tool proved invaluable was during a recent client case involving unknown parentage. The client’s DNA results showed a close match with someone sharing approximately 426 cM, with Ancestry predicting them most likely as a 1st cousin 2x removed. Using the Shared cM Project tool, I quickly determined that this match could be a first cousin once removed (1c1r), a half great-nephew, or a very close half-first cousin (Half 1c), along with a few lesser possibilities. This critical insight provided a starting point for further investigation, allowing me to zero in on specific family lines and greatly simplifying what could have been a lengthy process. This match wound up being a half great nephew, the grandchild of an unknown child who was the product of yet another affair of her father.

Another instance was during my own family research when I discovered another mystery match who shared approximately 201 cM with me. Initially, I had no idea how this person could fit into my tree. However, with the Shared cM Project tool’s suggestions, I was able to focus on the second cousin range as the most likely relationship, which eventually led me to an unknown child of my great uncle.

Why It’s My Go-To Tool for Client Work

For clients, the Shared cM Project tool is particularly useful because it streamlines the initial stages of DNA analysis. I can quickly interpret the data and explain potential relationships to clients, making the information accessible without overwhelming them with technical jargon. It’s also a fantastic educational tool when clients want to learn more about their DNA matches and what their results might mean.

How to Get Started with DNA Painter’s Shared cM Project Tool

If you’re interested in trying it out for yourself, DNA Painter’s Shared cM Project tool is free to use on the DNA Painter website. It’s a must-have for anyone serious about genetic genealogy, especially when working with DNA matches that aren’t immediately obvious. By simplifying the complex relationship possibilities that arise in DNA results, this tool has become indispensable in my toolkit.

Whether you’re a seasoned genealogist or a beginner just starting to explore the world of DNA, I can’t recommend DNA Painter’s Shared cM Project tool enough. It’s the kind of tool that evolves with you, adding precision to your research as you dive deeper into the fascinating world of genetic genealogy.

Shared cM Project Tool

​More Genetic Genealogy/DNA Resources

Find more DNA genealogy resources, tips, and other info under the Genetic Genealogy and DNA category.

​More Genealogy Resources

Learn about more family history and genealogy resources under the Genealogy Resources category and on my dedicated Genealogy Resources page.