At FamilyTreeDNA, a Y-DNA haplogroup prediction is calculated using genetic distance. The calculation finds your most likely haplogroup. The prediction program compares your Y-DNA STR (short tandem repeat) profile to our results database. The program uses the results of exact and near matches.
The process balances using a reliable number of Y-DNA STR markers and using a database of confirmed haplogroups that is sufficient in size. The program uses 14 Y-DNA STR markers for haplogroup predictions. These are the first 12 STR markers in all of our Y-DNA tests and two additional markers that we test as check values.
Should someone’s haplotype not be close enough to another for use to confidently predict a haplogroup, we confirm their backbone haplogroup placement according to our SNP Assurance Program.