I recently received my DNA matches from Ancestry, and I share 1,591 centimorgans across 53 segments with one, and 1,773 centimorgans across 58 segments with another.

Could these people be half siblings to me?


2 Answers 2



DNA Matches of 1,591cM and 1,773cM indicate half siblings as being a possible relationship.

On the strength of those matches the two people could also have one of these relationships to the person tested:

  • Grandparent/Grandchild
  • Aunt/Uncle/Niece/Nephew

but perhaps these can be ruled out on what you know of your family's generations.


Use The Shared cM Project 4.0 tool v4 that may be found on the DNA Painter website.

You can enter the number of shared CMs and see all the possibilities for how you are related to each of the matches.

  • 1
    While true, isn't that exactly the same tool linked from the other answer? Sep 9, 2020 at 14:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.