Most Recent Common Ancestor Calculator
Number of y-chromosome markers: Based on the Infinite Alleles Model. Note that this model underestimates the time to MRCA. This is relatively insignificant as sample markers increase beyond 25, but can be significant with fewer markers.
Average Mutation Rate: Please enter the number of markers and the mutation rate. Current studies suggest a mutation rate of .0043. Results will include up to 5 mismatches. More mismatches than this are probably not useful for most genealogical purposes.




Generations to MRCA
Probability of
Relationship %		 67 of 67


Matches

 66 of 67


Matches

 65 of 67


Matches

 64 of 67


Matches

 63 of 67


Matches

 62 of 67


Matches
25 0.6 1.8 3.1 4.5 5.9 7.4
30 0.7 2 3.4 4.8 6.4 7.9
35 0.9 2.2 3.7 5.2 6.8 8.4
40 1 2.4 4 5.6 7.2 8.9
45 1.1 2.7 4.3 6 7.7 9.4
50 1.3 3 4.7 6.4 8.1 9.9
55 1.5 3.2 5 6.8 8.6 10.4
60 1.7 3.5 5.4 7.2 9.1 11
65 1.9 3.9 5.8 7.7 9.6 11.6
70 2.1 4.2 6.2 8.2 10.2 12.2
75 2.4 4.6 6.8 8.8 10.9 12.9
80 2.8 5.2 7.4 9.5 11.6 13.8
85 3.3 5.8 8.1 10.4 12.6 14.8
90 4 6.6 9.1 11.5 13.8 16.1
95 5.1 8.1 10.8 13.3 15.8 18.3

This calculator is based on the Infinite Alleles Model as described in Estimating the Time to the Most Recent Common Ancestor for the Y chromosome or Mitochondrial DNA for a Pair of Individuals, by Bruce Walsh, Department of Ecology and Evolutionary Biology, University of Arizona, published June 2001 by the Genetics Society of America.