The expected relationship between you and your Y-chromosome DNA (Y-DNA) match is dependent on both the number of markers you have tested and the genetic distance. The chart below shows the interpretation of your relationship at each testing level (Y-DNA12, Y-DNA37, etc.) for relevant genetic distances.
For example, if you and your match have both tested at the Y-DNA37 level and are a 36/37 match, this is a genetic distance of one. You are then considered tightly related.
| Y-DNA12 | Y-DNA25 | Y-DNA37 | Y-DNA67 | Y-DNA111 | Interpretation | |
|---|---|---|---|---|---|---|
| Very Tightly Related | N/A | N/A | 0 | 0 | 0 | Your exact match means your relatedness is extremely close. Few people achieve this close level of a match. All confidence levels are well within the time frame that surnames were adopted in Western Europe. |
| Tightly Related | N/A | N/A | 1 | 1-2 | 1-2 | Few people achieve this close level of a match. All confidence levels are well within the time frame that surnames were adopted in Western Europe. |
| Related | 0 | 0-1 | 2-3 | 3-4 | 3-5 | Your degree of matching is within the range of most well-established surname lineages in Western Europe. If you have tested with the Y-DNA12 or Y-DNA25 test, you should consider upgrading to additional STR markers. Doing so will improve your time to common ancestor calculations. |
| Probably Related | 1 | 2 | 4 | 5-6 | 6-7 | Without additional evidence, it is unlikely that you share a common ancestor in recent genealogical times (one to six generations). You may have a connection in more distant genealogical times (less than 15 generations). If you have traditional genealogy records that indicate a relationship, then by testing additional individuals you will either prove or disprove the connection. |
| Only Possibly Related | 2 | 3 | 5 | 7 | 8-10 | It is unlikely that you share a common ancestor in genealogical times (one to 15 generations). Should you have traditional genealogy records that indicate a relationship, then by testing additional individuals you will either prove or disprove the connection. A careful review of your genealogical records is also recommended. |
| Not Related | 3 | 4 | 6 | >7 | >10 | You are not related on your Y-chromosome lineage within recent or distant genealogical times (one to 15 generations). |