This tool first predicts the most statistically likely relationship degree between two testers based on a formula provided by Marilynn Huff, and then allows you to answer a series of questions that will be used to filter the various relationship paths within that degree.

Note that especially for distant relationship degrees, the probability curves involved in tying a cM value to a specific degree become broad and overlapping due to the random nature of DNA inheritance.
(Tools like the shared cM project tool at DNAPainter explore the overlapping nature of the degrees, whereas this tool focuses primarily on exploring the possible paths within a degree.)

Degree Calculator

Select input type and enter your value to find the corresponding degree:


Degree: -

Number of relationship paths on the board: 0

Is Tester 1 from an older or younger generation than Tester 2?




How many generations separate the two testers?

Select Tester 1's gender.

Select Tester 2's gender.

From the perspective of Tester 1, on which side of the family is Tester 2:

From the perspective of Tester 2, on which side of the family is Tester 1:

How many centimorgans are shared on the X Chromosome?

(Entering any non-zero value will instruct this tool to assume that the MRCA responsible for the shared autosomal DNA is the same individual responsible for any shared DNA on the X chromosome, i.e. paths that include two consecutive males from either tester will be eliminated. Entering "0" will eliminate only those relationships where the lack of an X match would be impossible, such as paternal half-sisters. Entering a value less than 175 will rule out any paths where X recombination is impossible due to the laws of heredity, i.e. where the testers would be expected to match along the entire X chromosome. Leave blank if you wish to skip this filter.)

Do the testers share a Paternal (Y) Haplogroup?



(If you select "no," all paths that would result in the testers sharing a paternal haplogroup, i.e. direct paternal paths, will be eliminated. Indicating "yes" will instruct this tool to assume that the MRCA responsible for the shared autosomal DNA is a direct paternal ancestor, leaving only direct paternal paths remaining after applying the filter. Leave blank if you wish to skip this filter.)

Do the testers share a Maternal (mitochondrial) Haplogroup?



(If you select "no," all paths that would result in the testers sharing a maternal haplogroup, i.e. direct maternal paths, will be eliminated. Indicating "yes" will instruct this tool to assume that the MRCA responsible for the shared autosomal DNA is a direct maternal ancestor, leaving only direct maternal paths remaining after applying the filter. Leave blank if you wish to skip this filter.)

Based on your criteria, these are the most likely relationship paths for the two testers: