Try out the Shared cM Project Tool


21 July 2022
It's all very well knowing that you share a certain number of centiMorgans with a DNA match, but what does this mean? The Shared cM Project Tool is here to clarify for you...

The Shared cM Project Tool is available to study free of charge at

There are a few ways in which you can use it.

1. You can enter the number of centiMorgans that you and a match share in the box near the top of the Shared cM Project Tool. A table will then be displayed providing you with information as to what sort of relationship two people sharing that number of cM may have, and the likelihood of them having that relationship.

2. You can alternatively enter the % of DNA that you and a match share, and the same sort of table will be displayed.

3. You can peruse the entire table. This is an extremely useful exercise to undertake. Note for instance, the typical number of cM shared by a cousin (866 cM), say. Note too the range of cM that cousins may share: some first cousins may share as few as 396 cM, while other cousins may share as many as 1397 cM. 

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Learning about the typical number of shared cM, the wide range that may also be shared, and the likelihood of any of the relationships suggested is all extremely informative for your DNA discovery journey, helping you to work how where a DNA match may fit on your tree and what sort of relationship you may have with them.

Understanding how to use the Shared cM Project Tool is just one of the things taught on the DNA Bootcamp by DNA detective Michelle Leonard.

About the DNA Bootcamp

The DNA Bootcamp is an online 8-week DNA course for family historians tutored by Michelle Leonard and hosted by Family Tree. To find out more, get the dates in your diary, and to sign up for your place, click here. (Prices from £55 to £90).

PS Get the Workbook & Join the Group

When you book on the DNA Bootcamp starting 28 September you will also receive:

  • a digital copy of the 52 page DNA Workbook - packed with tips and tasks
  • & an invitation to join an exclusive DNA Facebook group that will run for the duration of the course

Any questions about the DNA Bootcamp, please email [email protected]

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